Colofon

Open Press Tilburg University

Tilburg, The Netherlands

© 2026 Frank G. Bosman

Design and typesetting: LINE UP boek en media bv

Cover image: Vatican city, Rome, Italy – Giuseppe Milo, https://gmilo.com

ISBN: 9789403860329

DOI: https://doi.org/10.56675/9789403860329

This is an Open Access book published under the terms of the Creative Commons 4.0 International license (CC BY NC ND 4.0). The full licence terms are available at creativecommons.org/licenses/by-nc-nd/4.0/legalcode.

dedication

For Timothy Eugene Geeringh,

the student whose honest questions inspired me to write this book.

Contents

dedication

Introduction. Why this book?

How to use this book

Acknowledgments

A note on historical dates

AI disclaimer

Part I: 101 Catholic tradition

Part II: 101 Catholic theology

Conclusion. And now the real work begins!

Appendix I: Dutch church history

Appendix II: Primers for Tilburg School of Catholic Theology

1. The academic code

Levels of publications

Genre of publications

Academic hierarchy

Academic degrees (general)

Useful online sources (general)

2. The theological code

Academic degrees (ecclesial)

Publications by the magisterium

Bible (and other classical literature)

Useful online sources (theology)

3. The ecclesial code

4. Academic hygiene

Forms of academic fraud

Citing: referencing and style sheets

Artificial Intelligence, academia, and theology

Introduction. Why this book?

Religion is a fascinating beast. It can elevate people, individually and collectively, to transcend their own selfish egocentrism and self-interest and replace these with care and responsibility for the common good. Religious rituals can help people overcome fear or anxiety, process grief, or mark existential moments in life. Religion can stimulate artists to paint, build, carve, and compose the monuments of any given culture. But religion also has the ability to subjugate people, to destroy and to blind, and to stimulate people to commit hideous crimes in the name of a divine entity.

Religion is an interesting phenomenon for sure, worthy of scrutinizing, criticizing, appreciating, discussing, and studying. Many people find themselves, at one point in their lives or another, drawn to this multi-faceted phenomenon. Some have intellectual or historical curiosities to appease, others want to reignite the faith of their youth, or have just embraced their new spirituality. But all those people can feel bewildered, puzzled, or even perplexed when confronted with the labyrinth that is any religion. Entering or being initiated in any religion can be a life-long intellectual and/or religious commitment.

Out of all the minor and major religions and spiritualities in the world, might they be in the present or have once been in the past, Christianity is among the most dominant ones. The Christian religion has more than two billion followers world-wide nowadays, approximately half of them being Roman Catholics, its largest denomination. This is, for one reason amongst many others, because of the historical connection between Christian evangelization and Western imperialism. For better and for worse, the Western colonial powers brought Christianity in their slipstream all over the known world. Christianity showed many faces in this regard: on the one hand, missionaries built hospitals, founded schools and orphanages, and cared in general for the sick and the outcasts, while on the other hand Christians all too often used Bible and tradition to accommodate, justify, and sometimes even instigate the oppression of, the discrimination against, and the cultural destruction of indigenous populations and cultures.

For all those interested in Christianity and all its intriguing theological nuts and bolts, a huge array of lengthy and intellectually daunting monographs has been written by various theologians, historians, and scholars of religion: enough to fill the legendary library of Alexandria all over again. Also, there are many, many short introductions to Christianity, all with their own particularities of course. All well and good, but these kinds of publications do not start at the basics: they still presume some prior knowledge as to who Jesus Christ was, what the Gospels are, or who the pope might be. But what happens when this is beyond your current intellectual grasp?

Of course, Christians have a world-spanning network of church communities. And within the overall majority of those communities, people are more than welcome to join their catechism courses, leading the newly-found believers to one or more initiation rituals. There is nothing wrong with that of course – a fish wants to swim and a monkey wants to climb. Christians want to evangelize; it is in their religious DNA. But what if you are interested in Christianity on a more intellectual note? What if you are seeking a more intellectual initiation instead of a religious one? And don’t forget, it has to be basic. Very basic. This book was written for all those searchers. Small in scale, considerable in its goal.

More easily accessible, intellectually sound introductions to Christianity and Christian theology are indeed needed. Many a theology student I have met during my years in Dutch academia and abroad, many a journalist I have given interviews to over the last decades, and many a friend and acquaintance whose sometimes lively, sometimes boring social gatherings I have survived, have all shown me that secularization’s most strong-headed child is religious illiteracy. Since the sixties of the 20th century, at least in the Western world, people have turned away, in different ways and degrees, from organized religion, a process described with words like secularization, individualization, de-institutionalization, and liquidation. To put it quite simply: Western people have left the Christian Church in all its denominations.

This has led, in the Western world specifically, not only to a great diminishment in the societal relevance of church organizations and communities, but also to a still greatly increasing decline in church attendance, financial contributions, and church facilities. Church buildings are closing down rapidly, while the remnants of a once powerful Church struggle to maintain structural and spiritual integrity. This has also led to religious illiteracy, that is, a lack of religious and specifically Christian socialization in the generations raised since the sixties. And this is problematic, I believe, not because the Supreme Being would be in dire need of worship and adoration by the masses, but because the Christian meta-narrative is of incredible historical influence to our modern-day society and culture, and has shown itself to be very persistent indeed.

Our legal system, our ideas about universal human rights, our political parties, our art and craftmanship, our history, our academic attitude, our ideas of retribution and righteousness, our relation with nature and our planet, the novels we read, the musicals we enjoy, the Netflix series we watch, even the games we play: we cannot understand them without our acknowledgement of their Christian heritage and resonance, and not without at least some basic understanding of that Christian tradition. Again, not because one has to believe in the existence of the Christian God – even though I would not object to such a thing – but because one cannot otherwise understand Western society as it is today.

In my work for the Tilburg School of Catholic Theology (part of Tilburg University, the Netherlands), I have come across many theology students of all ages, types of socialization, religious self-identifications, sexes, genders, and societal backgrounds. Some of my theology students were born and raised as (Roman) Catholics; usually they have a fairly decent idea of the basics of the Christian tradition, even though their relative privilege tends to make them blind towards their own biases. Other students are from different Christian denominations, also providing them with at least a basic understanding of Christianity, but – quite reasonably – leaving them often somewhat lacking in knowledge on the intricacies of (Roman) Catholic tradition; quite a challenge if one is studying Catholic theology.

Yet other students have recently converted to Christianity from an atheist, agnostic, or other non-Christian background, providing them with much fervor and enthusiasm no doubt, but also – usually – with quite some disadvantage in socialization too. Then there are students who do not identify as Christian or do not feel religiously inclined; they pursue theology because of an intellectual hunger, a feat that does not necessarily disqualify other, sometimes implicit, kinds of longing. Others may be drawn to a career in religion education or spiritual care. Many face the same momentous challenge before them: how to penetrate a religion intellectually without – sometimes – any prior knowledge of that faith? It is for them and for all the others, that this book was especially written. For those students – in academia or in life in general – who know (almost) nothing, but want to know everything.

This book is a very short and very basic introduction to Christian tradition and theology in general and Catholic tradition and theology specifically. Why Catholicism, you might ask? Not because there is no merit or goodness to be found in other Christian denominations or other religions and spiritualities. But wanting to write any book, let alone a very short introduction, on Christian tradition and theology in all its various and countless denominations is an impossible task for anyone. One has to choose a focus point, a point of departure, a lens through which one can look at the surrounding world. And my choice is to start from the (Roman) Catholic branch of Christianity. It is the Christian branch that I was born and raised on, the branch of Christianity that I studied and am still studying academically, and the branch where I still work every day.

How to use this book

This book has three parts, a very apt number for one on Catholic theology, as you will understand after finishing it.

The first part is on the Christian tradition in the broadest sense of the word. It covers the history and various traditions, Churches, and denominations of Christianity, with a focus on Roman Catholicism; not because of theological hubris, but because no book – how learned and voluminous it may be – can pretend to oversee all the corners and canyons of the Christian Churches, denominations, and movements at a single glance. This part covers topics like: the Bible (and why Christians spell it with a capital letter), the figure and significance of Jesus Christ, the tormented history of Christianity, the liturgical practices, and the sacraments, but also ecclesial (‘of the church’) structures and key figures. Finally, this part focuses on the relationship between Church and state (seen from the ecclesial perspective), some major topics of Christian ethics (including controversial ones, like abortion and euthanasia), the position of Mary, the Mother of God, and the relationship between Christianity and the other (world) religions (again from an ecclesial position). I will end this part by discussing some of the painful ‘dossiers’ that are also attached to the Christian tradition and that are very often associated with Christianity by its many internal and external critics: the crusades, the inquisition, its involvement in Western colonialism, its androcentrism, indulgences, and the matter of sexual abuse in pastoral relationships.

The second part is on Catholic theology, again in the broadest sense of the word. It covers the ‘classic’ theological tracts and it adds some new, contemporary ones. From discussions on God as Creator, Savior, and Whole-Maker (or Father, Son, and Spirit) via those on human nature, the Church, and the sacraments, to those on the other religions, on contemporary culture, and the world’s apocalyptic ending. It is inevitable that there is some overlap between Part 1 and Part 2, but the first is on Christian (Catholic) tradition, while the second is on Christian (Catholic) theology, the latter being a systematic reflection on the former.

In addition, there are two ‘localized’ appendices, one specifically dedicated to the (modern) history of religion in the Netherlands (and Belgium), and one specifically for aspiring novice students of theology at the Tilburg School of Catholic Theology. The latter covers the very basics of theology as an academic discipline at the beginning of the 21st century, including practical matters like reading, interpreting, and creating bibliographical data, using style sheets, and understanding academic genres (from journal articles to edited volumes), but also some pointers on ‘academic hygiene’ concerning the use of quotations and paraphrasing, as well as how to prevent plagiarism and other forms of academic ‘fraud’.

Acknowledgments

I want to thank my friends and colleagues who have been so kind as to read an initial version of this book and provide me with valuable overall feedback: William Arfman, Harm Goris, Sam Goyvaerts, Karim Schelkens, and Archibald van Wieringen. Special thanks to Maartje Groeneweg for her help in describing the Old Catholic Church in the Netherlands. ‘Oil and perfume make the heart glad, and so does the sweetness of a friend that comes from his earnest counsel’ (Proverbs 27:9 – own translation).

Also, I would like to thank all the students who have given their feedback during classes and other meetings: the students of the course ‘theological seminar’ of 2025/2026 at the Tilburg School of Catholic Theology, and those of the ‘Introduction Systematic Theology’ 2025 at the Saint Catharine’s Academy in ’s-Hertogenbosch/Rosmalen, especially Bart Verschuuren.

A note on historical dates

In this book I use the traditional Western calendar designations Anno Domini (Latin: ‘in the year of [our] Lord [Jesus Christ]’, abbreviated as AD) and Before Christ (abbreviated as BC). These terms have been in use for centuries. In modern academic and interfaith contexts, the alternatives Common Era (CE) and Before Common Era (BCE) are sometimes preferred because they provide a religiously neutral way to reference the same dates. Although CE/BCE were developed later, both systems refer to the same chronological framework. For clarity and consistency and because of the explicit Christian theological context of this book, I have chosen to use AD/BC throughout this book.

AI disclaimer

For this book, I have made use of ChatGPT as a conversational partner. This means that I have conversed with ChatGPT to brainstorm on structure, sequences, selections, et cetera, but not to write the texts for me.

Part I: 101 Catholic tradition

Writing a comprehensive and concise introduction to the Catholic tradition is a real challenge, as I said earlier in the Introduction. What I have tried to do, is to give a balanced overview of the most important part of that tradition from the perspective of a reader at the beginning of the 21st century who has had no or very little Christian socialization prior to picking up this book. The chapters in Part 1 cover:

A discussion on core terms and notions: what do terms like ‘Catholic’ and ‘Christian’ mean in the first place?

A short explanation of Sacred Scripture, both the Hebrew Bible/Old Testament and the New Testament.

A short discussion of the life, works, and religious stature of Jesus of Nazareth/Jesus Christ, arguably the founder of Christianity.

A very concise overview of two thousand years of Christian history, divided into five (rather arbitrary) eras.

A short explanation of the liturgical year, the eucharist as the most important Christian celebration, and some very important prayers.

A short overview of the Christian sacraments.

A concise introduction to the organization of the Catholic Church, including the terminology for officials and buildings.

An introduction to monasticism: men and women dedicating their lives in service of God and their fellow Christians.

An introduction to the social teachings of the Catholic Church.

An introduction to Christian moral reasoning, including the Ten Commandments.

A short overview of the notions of intercession, canonization, Mary, relics, and other objects related to the saints.

A list of ‘painful dossiers’, including androcentrism and the Inquisition, that also have to be addressed.

1. What do we mean with ‘Catholic’?

Before we can begin with a very basic introduction to Catholic tradition (and theology), we must first discuss what we mean with ‘Catholic’, because it does not mean the same thing in every context or to any individual Christian.

Catholicism (from the Greek katholos, ‘universal’) is an ambiguous term. It has at least three meanings. (1) In its broadest sense it is a synonym of ‘Christianity’ and therefore applicable to all Christians. (2) It can also refer to Western (‘Latin’) Christianity, after the Great Schism of 1054. But (3) it is also used as a shortening for and is therefore synonymous with ‘(Roman) Catholicism’, to the considerable chagrin of other Christians who opt for a more inclusive use of the word ‘Catholicism’. So, how boring that may be, we have to start with some more definitions.

Christianity (or Christendom) is a religion based on the teachings of Jesus of Nazareth as related in the New Testament (see Chapter I.2). It is comparable with other historical world religions like Judaism, Islam, or Hinduism, or new religions like wicca or neo-paganism. But things are never that simple. The Christian family is divided into multiple divisions or branches, called ‘denominations’. The most important (historically and quantitively) are: Oriental Orthodoxy, Eastern Orthodoxy, Protestantism (including the Anglican World Communion), and (Roman) Catholicism (see Scheme #1). They are all deserving of a short introduction, also to highlight their historical interdependence and origins.

Scheme #1 – Basic overview of major branches within Christianity and their points of separation.

Oriental Orthodoxy is a subsection of Christianity. It came into being in 451 (at the Council of Chalcedon) due to Christological controversies (see Chapter I.3 and II.4), when it separated itself from the rest of Christendom (technically known collectively as ‘Chalcedonian Christianity’). It is territorially or linguistically organized, that is, per land or per language, resulting for example in a Coptic Orthodox Church (Egypt), Armenian Orthodox Church (Armenia), or Syriac Orthodox Church (Syria).

Eastern Orthodoxy is another subsection of Christianity. It came into being in 1054 due to several theological and political controversies (see Chapter I.4 and II.2). Christianity split (called ‘the Great Schism’) into a Western part (or ‘Latin’ after its primary language) with Rome in Italy as its epicenter, and an Eastern part (or ‘Greek’ for similar reasons) with Byzantium (also known as Constantinople or modern-day Istanbul, Turkey) as its capital. The Western part developed into what we now call (Roman) Catholicism and Protestantism, while the Eastern part became present-day ‘Eastern Orthodoxy’, consisting of several ‘Eastern Orthodox Churches’.

It is territorially organized, that is, per country, resulting for example, in a Russian Orthodox Church, Greek Orthodox Church, or Serbian Orthodox Church. The Ecumenical Patriarch of Constantinople is regarded within Eastern Orthodoxy as their primus inter pares, or the ‘first among equals’. To complicate things even more, some Eastern Churches acknowledge the authority of the Pope, who is the Patriarch and Bishop of Rome, while maintaining their own liturgy and traditions.

(Roman) Catholicism is yet another subsection of Christianity, essentially (but certainly not exclusively) defined by acknowledgement of the supremacy of the Bishop of Rome, the Pope (see Chapter I.7). Roman Catholicism is one of the four major branches in Christianity, together with Eastern Orthodoxy, Oriental Orthodoxy, and Protestantism (including the Anglican World Communion). As indicated in the introduction, this branch of Christianity lies at the center of this book.

Protestantism (or the Churches of the Reformation) is another subsection of Christianity. It came into being in 1517 when the famous Catholic church reformer Martin Luther (1483-1546) publicly voiced his criticisms, ending in his formal ‘excommunication’ (expulsion from the world-wide Catholic community) by the pope. Seventeen years later, in 1534, the English monarch King Henry VIII renounced papal authority and created the Church of England (with the monarch at its head), leading later to the Anglican World Communion (including, for example, the Church of Ireland, the Scottish Episcopal Church, and the American Episcopal Churches), with the Bishop of Canterbury as its primus inter pares.

Both Reformations split Western Christianity into a Roman Catholic Church proper and the many denominations of Protestantism we have today, including (for example) Reformed Protestantism, Lutheranism, Evangelicalism, or the Anglican World Communion.

2. Sacred Scripture: the Hebrew Bible and the New Testament

The Bible (Greek: biblia (pl.), ‘books’) is the Christian word for Christianity’s sacred and foundational scripture, consisting of two parts, the Old Testament (very much like the Hebrew Bible of Judaism, or Tanakh) and the New Testament (exclusively belonging to Christianity). The Old Testament relates the history of the Israelite people from the creation of the world until and after their return from the Babylonian Exile. The New Testament relates the history of Jesus of Nazareth and the very early beginnings of Christianity, then still a sect within Judaism.

The books of the Tanakh were written, edited, and compiled by a vast army of authors and editors, somewhere between the 8th and 2nd century BC, very possibly based on older oral traditions that have not survived in any other form. Christians adopted the Tanakh under the name ‘Old Testament’ as their own, made some changes to the order of books, and added some extra books for various reasons. The New Testament was written much later, in the second part of the 1st century AD In Judaist-Christian interfaith contexts. The terms Old and New Testament are sometimes changed for First and Second Testament, since ‘old’ and ‘new’ suggest a theological ranking between the two faiths that did not prove to be conducive to mutual rapprochement and understanding.

Both parts, Old and New Testament, contain multiple books, differentiating in genre (chronicles, songs, narratives, poetry, letters, etc.), length, and content. The Bible is, therefore, a library containing individual books, not a coherent monograph written by one author (as for example the Quran is said to have been written by Muhammed). The scholarly discipline studying the texts of the Bible, their meanings, and their origins is called ‘exegesis’ (Greek: ‘to lead out’). Scholars doing exegesis are called ‘exegetes’ or ‘biblical scholars’.

The question as to how the events mentioned in the various books of the Bible are related to the historical events outside of those texts, is an interesting one, occupying the mind of exegetes and the faithful alike for a very long time. Biblical literalists and fictionalists stand in opposite corners of this debate, the former defending the absolute literal and historical accuracy of the biblical narratives, while the latter argue that these texts are interpretative, fictional representations of the interactions between God and humanity. However, what is and what is not ‘real’ or ‘true’ in or about the Bible, in any sense of those words, is open to continuous (historical and theological) debate.

Although they agree for the most part, various branches of Christianity all have their own biblical ‘canon’, their own authoritative list of sacred books, their ‘own’ version of the Old Testament, and use their own sequence of books. Literary works very familiar or similar to the traditional biblical books, but that were omitted for various reasons in the final canon of a given Christian denomination, are called ‘apocryphal’ (Greek: ‘hidden’). Books that are included in the Roman Catholic canon, but left out of the canon of most Protestant Churches, are regarded as ‘canonical’ by the former and ‘apocryphal’ by the latter. Because of religious sensitivities, these ‘contested’ books are nowadays also referred to as ‘deuterocanonical books’ (literally, ‘second-in-canonicity’).

Christians consider the Bible to be the ‘Lord’s Word’ (Latin: Verbum Domini). This has two interrelated but not mutually excluding, distinctive meanings. Many Christians consider the Bible to be the Word of the Lord: not in the sense that God wrote the Bible, but that the authors of the Bible books were divinely inspired by God. Other Christians consider the Bible to be the Word about the Lord: faithful people describing their relationship and vicissitudes with God.

The Old Testament

The original language of the Tanakh/Old Testament is Biblical Hebrew (and for some parts Biblical Aramaic and, for some deuterocanonical books, also Koine Greek). Historically very influential translations are the Septuagint in Koine Greek (3rd century BC by Jewish scholars) and the Vulgate in Latin (4th century AD by Christian scholars). The Old Testament is divided into five sections, generally based on their genre: Pentateuch, Historical Books, Wisdom Books, Major Prophets, and Minor Prophets.

Regarding vocabulary, things can be a bit complicated, since words like ‘Hebrews’, ‘Israelites’, and ‘Jews’ are frequently used, seemingly, interchangeably. ‘Hebrews’ denote the descendants of Abraham. ‘Israelites’ describe the descendants of Jacob, who is called ‘Israel’ (Hebrew: ‘Wrestler with God’). The word ‘Jew’ (Greek: Ioudaios; Latin: Iudaeus) became en vogue during the Hellenistic and later Roman occupation of the land of Israel. To be complete, the word ‘Israeli’ is used to describe a citizen or resident of the modern State of Israel (since 1948), irrespective of their religious or ethnic background.

Scheme #2 – A systematic overview of the Books of the Old Testament.

Pentateuch
(Greek: ‘in five scrolls’; in Judaism called the Torah, ‘what has to be learned’ or ‘the Law’.)

Genesis
Contains historically famous and culturally significant stories, like the creation of heaven and earth, Adam and Eve in the Garden in Eden, the Tower of Babel, the Deluge, and the so-called early ‘Patriarchs’, Abraham, Isaac, Jacob (who is named ‘Israel’), and Joseph. The last one takes his family to Egypt to escape a famine in their home country. [c. 1800 BC]

Exodus | Focuses on the figure of Moses leading the Israelite people (descendants of Jacob) from Egypt’s captivity through the desert to the ‘Promised land’ (then Canaan, present-day Israel) for forty years, including famous stories on the Ten Commandments and the worship of the Golden Calf. [c. 1200 BC]
Leviticus | Contain various codes of law, the Israelites’ trials and tribulations when wandering through the desert; kind of ‘add-ons’ to the Book of Exodus.
Numbers
Deuteronomy | Various speeches by Moses; a kind of ‘add-on’ to the Book of Exodus.
Historical Books
Joshua | Contains the conquest of the Promised Land (Canaan/Israel) by the Israelites under Joshua’s leadership, including the famous story of Jericho’s city walls tumbling down, and the division of the land among the twelve tribes of Israel.
Judges | Contains the cycle of Israel’s disobedience, oppression by foreign powers, and deliverance by judges chosen by God.
Ruth | Contains the story of Ruth, a Moabite widow who becomes an ancestor of King David through her loyalty to her mother-in-law, Naomi.

1 Samuel
2 Samuel
Focuses on the establishment of an Israelite monarchy under the reigns of Saul (1030-1010 BC) and David (1010-970 BC), the reign of ‘the wise’ Solomon (970-931 BC), the building of the 1st Temple in Jerusalem, the later division of the Israelite kingdom between Israel in the north and Judah in the south (931 BC), and their respective defeat by Assyria (including a total deportation in 721 BC) and Babylon (including an exile of the people’s elite and the destruction of the Temple in 587 BC).

1 Kings
2 Kings

1 Chronicles
2 Chronicles

Ezra | Focuses on the return from the Babylonian Exile (538 BC) and the building of the 2nd Temple in Jerusalem.

Nehemiah

Historical Books
(deuterocanonical)

Tobit | Relates the story of Tobias, who embarks on a journey with the angel Raphael to heal his blinded father Tobit.
Judith | Relates the story of Judith, an Israelite widow who kills the Assyrian general Holofernes.
1 Maccabees 2 Maccabees | Focuses on the Maccabean revolt (167-134 BC) of the Jews against the (Hellenistic) Seleucid Empire.
Wisdom Books
Esther | Relates the story of Queen Esther, who saves the Israelite people in Persia from a plot to destroy them.
Job | Relates a poetic exploration of the problem of suffering, with Job questioning God’s justice.
Psalms | Contains a collection of songs, prayers, and hymns expressing a wide range of emotions, from praise to lament.
Proverbs | Contains wisdom sayings and practical advice for righteous living.

Ecclesiastes
(or Qohelet)

Song of Songs | Contains a collection of erotic love songs, traditionally interpretated as a metaphor for the relationship between God and his people.

Wisdom Books
(deuterocanonical)

Wisdom | Contains wisdom sayings and practical advice for righteous living.

Jesus Sirach
(or Ben Sira)

Major Prophets
Isaiah | Contains prophecies of divine judgment over Jerusalem and the Israelite people, including the coming of a Messiah, a Chosen One, destined to be Israel’s salvation. Lamentations is traditionally considered to be written by Jeremiah.
Jeremiah
Ezekiel
Lamentations
Daniel | Contains the story of the prophet Daniel in Babylon during the Exile, including prophetic visions of future kingdoms.

Major Prophets
(deuterocanonical)

Baruch | Contains a letter of consolation and encouragement to the exiled Israelites in Babylon, emphasizing repentance and the hope of restoration. Baruch is traditionally considered to be written by Jeremiah’s secretary.

Minor Prophets

Hosea
Contain the various prophecies connected to their prophets, usually on social injustice towards the common people, on religious disloyalty of the Israelites towards God, and on punishment, forgiveness, and restoration by God.

The prophet Jonah is maybe the most well-known of the minor prophets because of his reluctance to prophesize on God’s instruction, for which he ends up swallowed up by ‘a large fish’, only to be spit out and proclaim Nineveh’s approaching destruction.

Joel

Amos

Obadiah

Jonah

Micah

Nahum

Habakkuk

Zephaniah

Haggai

Zechariah

Malachi

The New Testament

Almost all Christians do agree on the order and number of books contained in the New Testament. These were written in Koine Greek, the lingua franca of the Hellenistic world, including the Roman Empire. Famous old translations include the Latin Vulgate (4th century AD by Christian scholars) and the English King James Version of 1611. The New Testament is set up in five sections based on their genre: four Gospels, one Apostolic History, fourteen Pauline Epistles, seven other Apostolic Epistles, and one Apocalypse. We do not know much about the historical authors of the various books of the New Testament, but many of these books could very well be pseudo-epigraphs, texts attributed to but not per se written by a prominent biblical figure or author, with the purpose of gaining greater authority or credibility for the text.

Scheme #3 – A systematic overview of the Books of the New Testament.

Gospels
(according to…)

Matthew
All the four canonical Gospels relate the preaching, crucifixion, and resurrection of Jesus of Nazareth. Matthew, Mark, and Luke – who share many stories between their Gospels – are collectively known as the ‘synoptics’ (Greek: ‘seen together’). John has a more stand-alone position: his Gospel has much Sondergut (exclusive material). Stories about Jesus’ infancy can be found only in Matthew (including the ‘Wise Men’ and the Bethlehem infanticide) and Luke (including the shepherds).

Mark

Luke

John

Apostolic History

Acts
Narrates the very early history of the Christian Church, focusing on the work of the apostles, particularly Peter and Paul. It also relates the stories of Jesus’ ascension into heaven and the gift of the holy Spirit to Mary and the Apostles. It emphasizes the spread of the gospel from Jerusalem to the broader Roman world, guided by the same Spirit.

Very probably, Acts has the same author as the Gospel according to Luke.

Pauline Epistles
(Letter to the Christians of…)

Romans
Contains letters attributed to the Apostle Paul, a Jew and former critic of the early Jesus movement, who later converted (according to Acts) and travelled extensively throughout the Mediterranean world to establish new communities with whom he stayed in contact after his departure. Paul probably wrote his letters in response to written questions by the various new communities, but unfortunately those were lost to time, leaving us with only one side of the communication. Paul argued in favor of ‘gentiles’ (non-Jews) to enter freely into the Jesus movement (then still a sect within Judaism) without the necessity of converting to Judaism first.

Paul’s authorship of Ephesians, Colossians, 2 Thessalonians, Hebrews, 1 and 2 Timothy, and Titus is contested among biblical scholars.

Corinthians 1
Corinthians 2

Galatians

Ephesians

Philippians

Colossians

Thessalonians 1
Thessalonians 2

Hebrews

Timothy 1
Timothy 2

Titus

Philemon

Apostolic Epistles
(Letter by…)

James | Various letters attributed to several famous Christian ‘founding fathers’, including the Apostles James (Jesus’ brother according to Acts), Peter, John, and Jude.

Peter 1
Peter 2

John 1
John 2
John 3

Jude

Apocalypse

Revelation
Attributed to the Apostle John, it presents a number or visions concerning the end of the world. It includes famous scenes like the Lamb of God judging the living and the dead, the Four Horsemen of the Apocalypse, the ‘sign of the Beast’ (666), and the conflict between a dragon and ‘a woman’ (later often identified as Mary, the mother of Jesus). Historically, Revelation might very well be a veiled criticism of the Roman Emperor Nero and his persecution of Christians in the Empire.

3. Jesus Christ, Jesus of Nazareth: Son of God, Son of Man

Jesus Christ is the alpha and omega of Christianity, giving his name to the religion itself. He bears the theological title ‘(the) Christ’, while Jesus is his given name. The designation Jesus of Nazareth is also used, even though this never appears in the Bible itself. Christians typically use the name ‘Jesus Christ’, while ‘Jesus of Nazareth’ originated within the context of (modern) historical studies. About Jesus’ life, we are dependent on the four Gospels of the New Testament canon (from the second part of the 1st century AD), apocryphal literature (usually from the 2nd century AD or later), and some non-Christian sources that provide only the smallest amount of information (for example in the Annals by the Roman historian Tacitus or in the Jewish Antiquities by the Jewish historian Flavius Josephus, both works from the second part of the1st century AD).

In Christian tradition, Jesus is considered to be both fully God (‘Son of God’) and fully human (‘Son of Man’) (see Chapter II.4). The four Gospels view Jesus as the highly anticipated ‘Messiah’, the ‘Anointed One’ sent by God to deliver the world, establishing peace and justice in all the land. Such a savior figure was prophesized by various Old Testament prophets, like Isaiah and Jeremiah. In the New Testament, the Hebrew word mesiach became the Greek christos, Latinized to Christus, and later Anglicized to ‘Christ’. Because the Roman occupation of Israel (since 63 BC) was in full swing in Jesus’ days, the anticipation was that the Messiah would liberate the Jewish people from their foreign oppressors and restore the old monarchy.

Jesus of Nazareth

If we follow the New Testament Gospels as primary sources, Jesus of Nazareth was born into a Jewish family between 4 to 6 BC. That Jesus was born before ‘year 1’ is due to later calculational errors made by the 6th century monk Dionysius Exiguus, who was responsible for developing the chronological system that marks Jesus’ year of birth as ‘year 1’.

According to the ‘nativity Gospels’ (Matthew 1-2 and Luke 1-2), Jesus was conceived of the Holy Spirit and born of the Virgin Mary in Bethlehem, while the ancestry of her husband Joseph secured Jesus’ membership of the tribe of Judah, to which King David belonged, and thus Jesus’ pretentions to the throne. These ‘nativity Gospels’ are usually read together in the Christian tradition, leading to the famous nativity scenes seen everywhere around Christmas. It is a merger (or ‘harmony reading’) of Luke’s shepherds and Matthew’s magoi (later in history becoming the famous ‘Three Wise Men’ or the ‘Three Kings’).

After growing up – traditionally after his 30th birthday – Jesus became a traveling preacher-cum-miracle worker, proclaiming the approaching establishment of the ‘Kingdom of God’, while healing the sick, raising the dead, and exorcizing evil spirits. It is unclear whether this ‘Kingdom of God’ only denotes a local, worldly liberation of the Jewish people from Roman occupation or also the instalment of a universal, new reality in which all the evils of the world will be banished in favor of eternal blessings and happiness. He gathered a group of privileged friends around him, called ‘apostles’ (Greek: ‘emissaries’ or ‘delegates’) or ‘disciples’ (Latin: ‘pupils’ or ‘apprentices’), twelve in number, equal to the original twelve tribes of Israel.

Either way, Jesus’ unapologetic preaching ruffled quite some feathers, foremost of the Jewish political establishment. The Jews were given relative self-government under Roman occupation, a position that the Jewish religious and political leaders were all too keen to maintain, both for the sake of their entire people and for their own political and societal benefits. Jesus’ words and actions could inspire a general revolt against the Romans, an uprising that the Jews would probably not be able to quell, so they feared.

History, unfortunately, showed that their fear was not without grounds. The so-called First Jewish-Roman War (66-73 AD) led to the destruction of the Second Temple in 70 AD. And the Third Jewish-Roman War (132-135 AD), also known as the Bar Kochba Revolt, ended with massive devastation in the land and the renaming of the Roman province of Judea as (Syria) Palaestina.

Eventually, one to three years after the start of Jesus’ public ministry, a segment of the Jewish leaders conspired against Jesus, condemning him for blasphemy, since Jesus appears to have claimed to be the ‘Son of God’, a highly contested claim in any monotheistic context. They sentenced him to death, but they needed Roman approval for carrying out any death sentence. Seemingly reluctantly, the Roman governor Pontius Pilate ordered his soldiers to crucify Jesus, a particularly gruesome torture and execution device. The timing is highly symbolic in nature: Jesus’ trial and execution coincide with the Jewish Feast of Pesach, the solemn remembrance of Moses’ leading the Israelites from their Egyptian captivity as slaves, to their freedom in the so-called ‘Promised Land’.

After Jesus’ crucifixion and death just outside Jerusalem’s city walls, he was taken down from the cross and buried by some friends who remained loyal to him until the end. Three days later, some of his friends reported not to have found Jesus’ body in his burial tomb, claiming an appearance of heavenly messengers, who declared that Jesus was resurrected from the dead. The death and resurrection of Jesus Christ is the most important core tenet of the Christian faith. After several encounters between the disciples and the risen Jesus during forty days, he ascended before their eyes into heaven where he resides at the right hand of his divine Father, and from where he will come in glory at the end of times. Jesus’ disciples spread out over Jerusalem, Judea, and eventually the whole of the Roman Empire and even the entire then-known world, preaching a crucified and resurrected Messiah.

In recent years, numerous pseudo-scholarly narratives have floated around claiming that Jesus was in some kind of relationship with Mary Magdalene (who is mentioned in all four Gospels). The most famous example is The Holy Blood, the Holy Grail (1982) by Michael Baigent, Richard Leigh, and Henry Lincoln, eventually ending up as the primary inspiration source for Dan Brown’s world-famous novel The Da Vinci Code (2003) and its film adaption (2006). However, there is no historical or biblical evidence supporting a marriage by Jesus or his fatherhood, and since both are not explicitly mentioned in the New Testament, Christians assume Jesus lived and died a celibate.

Jesus Christ

In Christian tradition, God is incarnated (Latin: in carne, ‘in the flesh’) in Jesus of Nazareth (see Chapter II.4), in order to free all of humankind – and not only the Jewish people – from sin and eternal death, the latter being seen as the result of the first (see Chapter II.7). Jesus’ crucifixion is seen as a kind of offering or atonement to his divine Father on behalf of and by which humankind is again capable of entering the Kingdom of Heaven, just as Jesus’ subsequent resurrection from the dead is viewed as a manifestation of God’s continuous loyalty to those who are loyal to him. Therefore, the righteous will also be resurrected from their graves at the end of time, an undisclosed moment in the future when the Son of God will return to Earth to judge ‘the living and the dead’, that is, all of humankind (see Chapter II.12).

From a monotheistic perspective, God having an equally divine Son is of course quite a theological problem. Incidentally, the Christian faith has indeed been accused of polytheism. Things got even more complicated when the Holy Spirit entered the theological arena, an equally divine entity promised by Jesus to his followers to guide and help them after his ascension to heaven, and given to them at Pentecost (when, according the Book of Acts, the Holy Spirit descended upon Mary and the Apostles in the form of fire). Together, God the Father, God the Son, and God the Holy Spirit form the ‘Holy Trinity’ (Latin: trinus, ‘threefold’): one in essence and being, but nevertheless distinguishable from one another. This theological construction did, however, not end theological and other debates on how something or someone can be one and three at the same time (see Chapter II.2).

Even though Christianity started as a Jewish sect, Jews and Christians eventually separated over a very long and painful process taking between one and four centuries (opinions vary strongly). After the split was final and Christianity had spread over the then-known world, Christians could act quite violently towards their former co-believers. The most notorious (and false) Christian accusations against the Jews, were the so-called deicide-notion and ‘blood libel’.

The blood libel suggested that Jewish communities used the blood of Christian children in religious rituals, particularly in the preparation of the Passover matzah (unleavened bread). The deicide-notion was the idea that it was not only that the Jews of the 1st century AD were responsible for killing God (through crucifying Jesus), but that the punishment of this hideous crime was transferred to all Jews since. Christian antisemitism, unfortunately, would not die out in the next two millennia and it can still be found within some parts of Christendom (see Chapter I.12).

4. Struggles, schismata, and Reformations: church history

Christianity originated in Judea, but spread quickly, first over the Roman Empire (southern Europe, northern Africa, the Middle East) and even beyond (western India), and then, in several steps, over the whole world. Any attempt to make a concise, all-encompassing overview of a process of this complexity and magnitude is perilous at best, and pretentious at worst. Nevertheless, I will try to do precisely that. For this book, I have chosen to divide Christian history into five eras:

The persecuted Church: from Jesus’ death (33) until the Edict of Milan (313)

The privileged Church: from the First Council of Nicaea (325) until the coronation of Charlemagne (768)

The Eurocentric Church: from Charlemagne’s death (814) until the Reformation (1517)

The global Church: from Columbus’ discovery of the New World (1492) until the start of the Second Vatican Council (1960)

The challenged Church: from the end of the Second Vatican Council (1965) until the present day.

I end with some short observations on Dutch church history and its particularities, since this book was written in the Dutch context.

The persecuted Church

The Early Church proper started with the death and resurrection of Jesus Christ, who urged his followers to preach his gospel of the Kingdom of God to the ends of the known world. Initially, the followers of Jesus were a small but distinct group within Judaism: Jews who saw Jesus as the Messianic savior prophesized in the Hebrew Bible. Due to missionary activities, amongst which the Apostle Paul has an important role, relatively large amounts of ‘gentiles’ (or non-Jews) poured into the young Jesus movement. This division within the movement would lead to a long process of separation (as discussed shortly in the previous chapter). With the influx of ‘gentiles’, the traditional Jewish theology of the Jesus movement was paired with Greek philosophy, especially that of Plato (c. 427-347 BC) and Aristotle (c. 384-322 BC), and their intellectual descendants. Until this day, Christian theology is a mix between Jewish and Hellenistic thinking.

The Christian faith – often indistinguishable from Judaism for the uninitiated, especially in the earlier days – was not always welcomed in the Roman-Hellenistic world of the Mediterranean: emperors like Nero (54-68), of whom the Bible book Revelations speaks as ‘the Beast’, Domitian (81-96), Decius (249-251), Valerian (253-260), Diocletian (284-305), and Galerius (305-311) destroyed churches, burned Bibles, and imprisoned, tortured, and executed Christians. However, times of persecution and those of relative peace alternated quite frequently, depending on various factors. Christian leaders, however, used these times of tribulation and victimhood to promote the spiritual and moral superiority of the new religion, since its adherents were prepared to give their own lives at martyrs for their faith in Jesus Christ.

Historically, nevertheless, the Christians were not so much persecuted for the content of their faith, as for their corresponding headstrong refusal to sacrifice to the Roman gods, especially to the deified emperor. The Roman Empire was known for its religious tolerance, but it demanded that every resident of the empire pledge allegiance to the state. The form of this allegiance was typically a burnt offering to gods and emperor, something the Christians were generally not prepared to do because of their strict monotheistic views. Within the young Church, bishops and other authority figures discussed what to do with lapsi (Latin: ‘fallen ones’), those who gave in to Roman pressure during a time of persecution but wanted to return to the Christian community in safer times.

Important thinkers of this era include Justin Martyr (c. 100-165), Irenaeus of Lyon (c. 130-202), Clement of Alexandria (c. 150-215), Tertullian (c. 185-253), Cyprian of Carthage (c. 200-258), Hippolytus of Rome (c. 170-235), and Origen of Alexandria (c. 185-253/4).

The privileged Church

The situation of the Church changed dramatically for the better in 313, when the Roman emperor Constantine the Great issued religious tolerance and freedom through the Edict of Milan. This edict ended the period of persecution. In 380, 67 years later, through the Edict of Thessalonica, the emperors Gratian, Valentinian II, and Theodosius I declared Christianity as the state religion of the Roman Empire. This not only drastically improved the situation of Christians and Christianity, but anchored it in one of the pivotal economic, social, and political powers in all of Europe, a position it would hold for almost one and a half millennia.

In the meantime, the Roman Empire faced severe political difficulties. In 395, the empire effectively split up in two parts: an Eastern (‘Byzantine’), Greek-speaking Roman Empire that would continue to thrive for more than a millennium, until the fall of its capital Constantinople in 1453 at the hands of the (Islamic) Ottoman Empire; and a Western, Latin-speaking Roman Empire that survived only until 476, when Germanic tribes conquered Rome’s heartlands. Even though the majority of these ‘barbarians’ would gradually convert to Christianity, Europe ceased to be a unified political entity and broke down into a patchwork of smaller kingdoms, each with varying and quickly changing degrees of allegiance to one another. It was only under Charlemagne (‘Charles the Great’), King of the Franks (748-814), that the Holy Roman Empire (of German Nations) was founded, a kind of spiritual successor to the original Western Roman Empire, unifying (again) modern-day France, Germany, the Low Countries, Switzerland, Austria, and parts of Italy.

Regarding church politics, this was the era of fundamental theological discussions about the nature of God and Jesus Christ, discussions that might seem irrelevant and archaic from the perspective of the 21st century but that are important to understand the historical development of Europe and the Christian Church as a whole. The Ecumenical Councils (deliberative gatherings of church leaders worldwide) of Nicaea I, Ephesus (431), and Chalcedon (451) discussed the nature of Jesus Christ in the context of heterodox (non-orthodox) groups like the Arians (Jesus had one ‘nature’, a human one) and Monophysites (Jesus had one ‘nature’, a divine one). The majority of the bishops gathered at the Councils judged that Jesus Christ had two natures – a divine and a human one – that were indistinguishable and inseparable from one another. Of course, what is and is not deemed ‘orthodox’ or ‘heterodox’ (or ‘heretical’) can only be established in hindsight, since these judgments are shaped by the theological, political, and cultural contexts that evolve over time, often influenced by the dominant power structures within the Church (see Chapter II.1).

Other theological discussions were about – among others – the nature of the relation between God the Son and God the Father. The First Councils of Nicaea (or Nicaea I) and the First Council of Constantinople (or Constantinople I) (381) stressed that both are homoousios (Greek: ‘of one substance’ or essence). Both Nicaea I and Constantinople I contributed to the so-called ‘Nicene-Constantinopolitan Creed’ (the Nicaeno-Constantinopolitanum), a still very authoritative summary of the Christian faith.

The Second Council of Nicaea (or Nicaea II) (787) resolved a dispute on ‘iconoclasm’, the idea that images (specifically icons) and other religious iconography were unsuitable for veneration (because of idolatry). Nicaea II, however, declared that icons could be venerated but never adored. A local Council at Carthage (411) condemned Donatism, the idea that the workings of church blessings and sacraments rely on the holiness of the one administering them. The Council, however, proclaimed that sacraments work in and of themselves.

The period from c. 100 until the Second Council of Nicaea is known as the Patristic era: the theologians of this period are the ‘fathers’ (Latin: patres) of Christian theology. Usually, they are categorized by the language they wrote in: Latin or Greek. Famous theologians of this era include Athanasius of Alexandria (296-373), Augustine of Hippo (354-430), Basil of Caesarea (330-379), Gregory Nazianzen (329-390), Cyril of Alexandria (376-444), Leo the Great (400-461), Maximus the Confessor (c. 580-662), and John of Damascus (676-749).

It was also the time of the birth of monasticism (see Chapter I.8): a religious way of life in which individuals, collectively (‘coenobitic’) or individually (‘eremitic’), commit to a secluded life dedicated to prayer, asceticism, and spiritual growth. The male and female monastic life typically involves vows of poverty, chastity, and obedience, with a focus on contemplation, work, and prayer/liturgy. In Christianity, monasticism began with figures like Anthony the Great (251-356) and Benedict of Nursia (480-547). Benedict’s ‘rule of life’ became foundational for Western monasticism, emphasizing obedience (to an abbot or leader of the community), stability (to remain in one monastic community), and communal living (sharing everyday life with one’s brothers or sisters). Monastic communities are typically mono-gendered.

The Eurocentric Church

The period between Charlemagne’s death in 814 until the Reformation started in 1517 is characterized by the dominance of Christianity in Europe, a situation that would not be challenged until the second half of the 20th century. Present-day France, Germany, Ireland, England, and the Low Countries (nowadays Belgium and the Netherlands) had already been Christianized in earlier days, but Hungary, Poland, Russia, Scandinavia, Bohemia, and Lithuania would soon follow. Feudalism became the dominant political structure for Europe, with various higher and lower kings, princes, lords, and vassals forming intricate networks of loyalty and land control, significantly limiting any possibility of a centralized authority. The nobles formed quickly-shifting alliances and often waged devastating wars against one another.

One of the most important conflicts of Western Europe was the Hundred Years’ War (1337-1453), a prolonged series of conflicts between England and France, primarily over territorial disputes and claims to the French throne. The conflict ended with France emerging victorious, marking the decline of English influence in France and significantly shifting medieval European power structures. During the same period, bubonic plague, the so-called ‘Black Death’ (1347-1351) raged through Europe, killing an estimated one-third of the population. The plague, likely spread by fleas on rats, caused widespread social, economic, and cultural upheaval, significantly weakening the feudal system and altering Europe’s demographic structure dramatically.

Since the beginning of the 7th century AD, a new religion emerged from the Arabian Peninsula, Islam (founded by a prophet called Muhammed). After the initial rapid spread of this religion across the Middle East, North Africa, and the Iberian Peninsula, Islamic empires such as the Abbasid Caliphate (750–1258) oversaw a golden age of cultural, scientific, and intellectual achievements. The rise of the Seljuk Turks and later the Ottoman Empire marked the continued influence of Islam, particularly in the Eastern Mediterranean. This culminated in the fall of Constantinople, the capital of the Eastern Roman Empire (Byzantium), in 1453. On the Iberian Peninsula, the Emirate of Córdoba flourished as a center of learning until the 8th century Christian Reconquista began reclaiming territory, culminating in the fall of Granada in 1492. From 1095 until 1291, Western powers besieged Jerusalem and wrested larger parts of present-day Israel, Lebanon, and Syria from Muslim control during a series of religiously motivated military campaigns known as the Crusades. Unfortunately, the crusaders were rather indiscriminate in choosing their victims: Jews, Muslims, and Eastern Orthodox Christians were all targeted at various points.

In 1054, the Filioque-dispute led to the Great Schism between the Western (Latin) Church and the Eastern (Byzantine) Church, the former keeping, the latter disqualifying the idea that the Holy Spirit proceeds through not only the Father but also the Son (Latin: filio-que, ‘and through the son’) (see Chapter II.2). Other, probably more pressing and practical reasons for the split were the questions of primacy between the Bishop of Rome and the Patriarch of Constantinople, as well as political tensions of various natures. Even though the papacy gathered political dominance in the Western world, its legitimacy was challenged several times, especially when multiple contenders to the papal throne were competing with one another. For example, in the period 1309 until 1376, popes and anti-popes, located in Rome and Avignon (France), were excommunicating one another during a very difficult dispute about succession. Only in hindsight, are the Avignon popes considered to have been the legitimate ones.

The dominant theological ‘school’ of this era is undoubtfully Scholasticism, a medieval intellectual movement that sought to reconcile faith and reason, emphasizing the use of reason and logic to understand and explain the Christian faith. It is connected to the rise of the universities in Europe, especially in Bologna (since 1088), Paris (since 1150), Oxford (since 1096), Cambridge (since 1209), and Louvain (since 1425). The most famous theologians of this era include: Anselm of Canterbury (1033/4-1109), Hildegard von Bingen (1098-1179), Peter Abelard (1079-1142), Bonaventure (1217-1274), Thomas Aquinas (1225-1274), Duns Scotus (1266-1308), Bridget of Sweden (1303-1373), William of Ockham (1287-1347), Juliana of Norwich (1342-1416), and Catherine of Siena (1347-1380).

Important philosophical and theological discussions include the ‘problem of universals’ and the free will versus grace debate. In the first, realists and nominalists discussed the relation and priority between reality and our human concepts of that reality. In the second, theologians discussed the relationship between humanity’s free will, the necessity of divine grace (God interfering in the human world), and the possibility of predestination (the idea that humans’ choices are already predetermined by God).

This last discussion also contributed to the Reformation, started in 1517 by Martin Luther. Other famous Reformers include John Calvin (1509-1564), Huldrych Zwingli (1484-1531), Philipp Melanchthon (1497-1560), and John Knox (c. 1514-1572). The Reformers voiced objections against the ‘orthodox’ stance towards free will and divine grace, the authority of the Bible, the role of the clergy, the importance of the sacraments, and the practice of indulgences. Eventually, Western Christianity split into a Roman Catholic Church proper and the various Protestant denominations we still have today.

In this period, the famous mendicant orders of the Franciscans and Dominicans were instituted by Francis of Assisi (c. 1181-1226) and Dominicus de Guzman (1170-1221). Mendicant orders embrace poverty, itinerancy, and urban ministry, focusing on preaching and serving the poor. Unlike earlier monastic traditions, which centered on stable, self-sufficient communities that held property and supported themselves through work, the mendicants rejected property ownership and trades, choosing instead a mobile life grounded in voluntary poverty and evangelization.

The global Church

In the meantime, from the 15th century, a new age of exploration dawned on the Western world. This event marked the beginning of widespread European colonization and the establishment of global trade networks. The ensuing encounters between European powers and indigenous populations led to significant cultural exchanges, but also to conflicts, exploitation, and the spread of Christianity as a dominant global religion. Often, the Christian missionaries followed in the footsteps of the Western explorers, usually equally keen on theologically defending Western dominance as on erecting a wide system of welfare, education, and health care throughout the new world. This age brought Western powers, especially Spain, Portugal, England, France, and the Netherlands, to the level of world domination (militarily, economically, and politically), a position they would hold until just after the end of the Second World War.

Culturally, this was the period of the Renaissance, spanning roughly from the 14th to the 17th century: a period of cultural, artistic, and intellectual revival in Europe and the Ottoman Empire, inspired by a renewed interest in the classical antiquities of Greece and Rome. The Renaissance (French: ‘rebirth’) marked significant developments in art, literature, science, and philosophy, with figures like Leonardo da Vinci (1452-1519) and Michelangelo (1475-1564), whose work are still considered to be amongst the greatest of the Western world.

The (artistic) Renaissance flowed over into the Enlightenment (the intellectual Renaissance), from the 17th to the 18th century, an intellectual and cultural movement emphasizing reason, science, and individual rights over tradition and secular and religious authority. Thinkers like Hugo Grotius (1583-1645), Voltaire (1694-1778), John Locke (1632-1704), and Immanuel Kant (1724-1804) tried to establish a modern society without any claim to divine constitutions, not because they did not believe in God, but because they believed that such a basis would always lead to more (religion-inspired) political conflicts. Politically, this period also signified the rise of democracy and new discussions on the relationship between the state and (institutionalized) religion, especially materializing in the ideals of the American War of Independence (1775-1783) and the French Revolution (1789-1799).

For the Catholic Church, this period is not only one of world-wide evangelization, in constant competition with various Protestant denominations, but also – in Europe – of the Counter-Reformation, starting with the Council of Trent (1545-1563). Both were aimed at combating the Protestant Reformation as well as revitalizing the Catholic Church through internal reform. Catholic theologians and church officials stressed certain parts of Christian doctrine, especially regarding the sacraments, made the liturgy (Tridentine Rite) and catechetical instructions (Roman Catechism) uniform, reformed the practice of indulgences (one of the triggers for the Reformation), reaffirmed the connection between Bible and Tradition, stimulated Baroque art and personal devotional practices, reformed monastic orders, and erected seminaries as the proper place of training priests-to-be.

The ‘Donation of Pippin’ in 756 AD marked the beginning of the Papal States as a territorial power, granting the pope control over a sizable portion of central Italy surrounding the city of Rome. This authority lasted for centuries, even if the actual geographical size of the Papal States would fluctuate under various political and military forces. In 1870, however, the Italian king Victor Immanuel II and Guiseppe Garibaldi captured Rome, leaving (and lending) only one of Rome’s hills on the right bank of the River Tiber to the pope, the Vatican Hill, with Saint Peter’s Basilica at its center. The First Vatican Council (1868-1870) was adjourned because of this capture and was never formally concluded. The Council is famous or infamous – depending on one’s theological position – for the declaration of the dogma of papal infallibility, the idea the pope can declare certain ‘truths’ ex cathedra, that is, truths to be held by the whole Church as such. It has been used only once since, in 1950, when Pope Pius XII declared the Assumption of Mary to Heaven with Body and Soul as a Catholic dogma.

Important theologians of this era include: Ignatius of Loyola (1491-1556), founder of the Jesuits, the Spanish mystic Teresa of Avila (1515-1582), Friedrich Schleiermacher (1768-1834), John Henry Newman (1801-1890), and Pope Leo XIII (1810-1903). The last is famous for kickstarting the notion of Catholic social teaching with his encyclical Rerum novarum (1891). The Catholic Church was certainly not the first Christian branch to align itself with the new social order – separation of Church-state, freedom of religion, democracy, workers’ and women’s rights, and the like – but caught up quickly through multiple encyclicals by various popes after Leo XIII, focusing on the ideals of the common good (bonum commune), solidarity, subsidiarity, and human dignity.

The challenged Church

During the 20th century, Western Europe and – to a lesser extent – the United States of America secularized quickly. Increasing numbers of Western citizens turned away from traditional religious self-identification. The Netherlands and the Scandinavian countries were among the avant-garde of this phenomenon, while Eastern Europe was forcibly secularized under communist rule after the Second World War. This secularization happened in two steps. First, from the 1960s to the 2010s, many people turned away from institutionalized religion, that is, they stopped being involved in local church activities, and usually began to embrace a more individual spirituality as a kind of substitute. Secondly, from the 2010s onwards, people also turned away from this ‘free spirituality’, ceasing to identify as religious or spiritual altogether. This put immense strain on all church organizations, leading to a rapid decline in church attendance, membership, financial viability, buildings, and other assets, and leading to the massive closure of church buildings and the mergers (or even dissolution) of religious communities. Simultaneously, this meant a significant diminishment in the relevance of the (Christian) Church for society, politics, and culture. It is still to be seen if the rest of the world will follow the Western example (and how), and if this secularization is permanent or has come to an end (or not).

Paramount in the modern history of the Catholic Church is, undoubtedly, the Second Vatican Council (1962-1965). Called by Pope John XIII and finalized by his successor Paul VI, the theme of the Council was aggiornamento (Italian: ‘update’): the conscious effort to bring the Catholic Church ‘up to speed’, so to say. The Council’s agenda ran along two principal axes. First, it pursued an internal reconfiguration of the Church: a renewed appreciation of the role of the laity; an emphasis on baptism as the foundational locus of ecclesial identity; significant developments in the theology and practice of the sacraments and the liturgy; and a rebalancing of ecclesial authority that was less centered on the papacy and more attentive to the episcopate. Second, the Council marked a decisive turn toward the principles of tolerance, understood in a manner broadly consonant with Locke’s conception of religious liberty, and toward sustained dialogue: with the modern world, with other Christian communities, and with other religious traditions.

The most important theologians of the era are, among others, Rudolf Bultmann (1884-1976), Karl Barth (1886-1968), Paul Tillich (1886-1965), Karl Rahner (1904-1984), Yves Congar (1904-1995), Marie-Dominique Chenu (1895-1990), Henri de Lubac (1896-1991), Rosemary Goldie (1916-2010), Rosemary Radford Ruether (1936-2022), Piet Schoonenberg (1911-1999), Edward Schillebeeckx (1914-2009), Jürgen Moltmann (1926-2024), Joseph Ratzinger (1927-2022), Gustavo Gutiérrez (1928-present), Hans Küng (1928-2021), Wolfhart Pannenberg (1928-2014), and Walter Kasper (1933).

5. From Christmas to Easter, and back again: liturgy

Liturgy (Greek: leitourgia, ‘public duty’ or ‘public service’) is the complex of public and communal worship within the Christian tradition, encompassing the rituals, ceremonies, prayers, and the celebration of the sacraments through which the community of the faithful expresses and embodies its faith in Jesus Christ. Liturgy is, therefore, not merely a set of prescribed words and actions but a ‘place’ (or ‘event’) where the faithful participate in Christ’s salvation. Liturgy is a dynamic interplay of words, symbols, gestures, and communal dialogue.

Even within the Roman Catholic tradition, liturgical practice is far from uniform, since it formally recognizes more than twenty distinct rites, each with its own historical trajectory, theological emphases, and ritual expressions. Since it is impossible to describe this full liturgical plurality in detail, the present discussion will focus on the dominant rite of the Roman Catholic Church in the Western world, the so-called ‘Latin rite’ or ‘Roman rite. This rite has undergone substantial development, particularly in the aftermath of the Second Vatican Council, that sought a ressourcement (renewal through returning to Early Christian sources) and aggiornamento (the updating of liturgical forms to meet the pastoral needs of modern communities). These reforms emphasized active participation, the centrality of Scripture, and the dialogical nature of worship.

The liturgical year

Every Christian branch has its own interpretation of the liturgical year. The liturgical year consists of an annual cycle of seasons and feasts, usually but not exclusively connected to the life and works of Jesus Christ (see Chapter 2).

The two major liturgical cycles are Easter and Christmas. The first one commemorates the death and resurrection of Jesus Christ, the second one his birth. Christmas is celebrated on a fixed date, December 25, while the Easter date variates between March 22 and April 25. This calculation is based on the ecclesial approximation of the March equinox and the lunar cycle, which does not always align perfectly with the astronomical equinox and actual full moon. Many other feasts and seasons are linked to these two major ones, even though others have their own fixed date. Other Christian denominations, especially the Eastern Orthodox Churches use a different calculation, resulting in different Christians celebrating, for instance Easter, on different dates in the same year.

Liturgical periods all have their own distinct color. This means that during a specific part of the liturgical year, the dominant (but not necessarily exclusive) color used in the liturgy identifies that part as such. This includes the vestments of the presiders of the liturgy and other objects in and around the church.

The liturgical year begins with Advent, four Sundays before December 25, preparing for the feast of Christmas. During the four Sundays of Advent, the faithful light four candles – every Sunday one more – to symbolize the approach of the birth of Christ, the ‘Light of the World’. Liturgical color: purple.

Next, the Christmas season (also known as Christmastide) starts with the Feast of Christmas itself and ends with the Feast of the Baptism of Jesus in the River Jordan on the Sunday after Epiphany (which commemorates the visit of the Magi). Liturgical color: white.

Then, the first (shorter) period of what is called ‘Ordinary Time’ starts. It starts after the Christmas season and lasts until the beginning of Lent. Liturgical color: green.

Lent is a period of forty-six days of preparation for the Feast of Easter, beginning with Ash Wednesday. Catholics fast during this period, except on the Sundays (effectually leaving forty days of fasting, like Jesus did in the desert). Liturgical color: purple. In earlier days this fast meant abstaining from eating meat and luxury foods (including candy); nowadays the faithful also fast in other ways, like abstaining from alcohol or social media.
Sundays in this period are part of Lent, but not part of the fasting. The last week of Lent is called the ‘Holy Week’, which also includes the Easter ‘Triduum’.

The Easter Triduum contains the three holy days of Pascha, usually seen as one big celebration: Maundy Thursday (‘Holy Thursday’) commemorates Jesus’ Last Supper (liturgical color: white); Good Friday commemorates Jesus’ crucifixion (liturgical color: red); and on the Saturday evening, the Easter Vigil commemorates Jesus’ resurrection (liturgical color: white).

Easter season (also known as Eastertide) starts with Easter Sunday, includes the Feast of the Ascension of the Lord (commemorating the risen Jesus Christ ascending into heaven) on the 40th day of Eastertide, and ends with Pentecost (commemorating Mary and the Apostles receiving the Holy Spirit) on the 50th day of Eastertide. Liturgical color: white (except on Pentecost: red).

Finally, there is a second (longer) period of Ordinary Time, starting after Pentecost and lasting until Advent, before the whole cycle starts all over again. Liturgical color: green.

The liturgical year includes many more major and minor feasts and commemorations, usually connected to Jesus Christ, Marry, or various saints and martyrs. These may vary per country or even diocese.

Important prayers

The Roman Catholic liturgy has many songs, hymns, and prayers. The two most important are listed below. The Lord’s Prayer is the central prayer of all Christendom, traditionally said to have been taught by Jesus to his disciples (Matthew 6:9-13 and Luke 11:2-4). The Roman Catholic version is as follows (different Christian denominations have a different rendering of the same text):

Our Father who art in heaven,

hallowed be thy name.

Thy kingdom come,

Thy will be done on earth, as it is in heaven.

Give us this day our daily bread,

and forgive us our trespasses,

as we forgive those who trespass against us,

and lead us not into temptation,

but deliver us from evil.
For the kingdom, the power and the glory are yours

now and forever.

Amen.

The Hail Mary is another very important prayer, especially in the Roman Catholic tradition, and is based on the biblical stories of the angel Gabriel’s greeting to Mary (Luke 1:28) and Elizabeth’s exclamation (Luke 1:42), later expanded with a petition for her intercession.

Hail, Mary, full of grace,

the Lord is with thee.

Blessed art thou amongst women

and blessed is the fruit of thy womb, Jesus.

Holy Mary, Mother of God,

pray for us sinners,

now and at the hour of our death.

Amen.

The Apostles’ Creed is a very early summary of the Christian faith, traditionally attributed to the twelve Apostles (hence its name), and expressing core tenants of the faith. The Creed of Nicaea-Constantinople is also an authoritative summary of the Christian faith. This creed was formulated at the First Council of Nicaea and the First Council of Constantinople (381). It is much more theological-technical in nature than the Apostles’ Creed.

6. Seals & Signs: the seven sacraments

Christianity has various sacraments: special rites, associated with the life and work of Jesus Christ, and serving as outward signs for inward spiritual transformations and realities. Roman Catholicism has seven different sacraments: baptism, the eucharist, confirmation, reconciliation (or confession), the anointment of the sick, matrimony, and ordination (see Chapter II.8).

The first three sacraments – baptism, the eucharist, and confirmation – are aimed at initiating a person into the community of the Church. This initiation is always in a local community: you do not become ‘just’ a Christian but, for example, a Roman Catholic, a Reformed Protestant, or an Anglican. In the case of the Catholic Church, after your initiation you are welcome to join the eucharist every Sunday (or even every day of the week.) Two of the seven sacraments – reconciliation (confession) and the anointment of the sick – are ‘healing’ sacraments, that is to say, they are aimed at healing the believer’s soul (and body). Two others – marriage and ordination – are aimed at guiding and enabling believers to a ‘place of service’ within their faith communities.

Baptism

The sacrament of baptism (Greek: ‘immersion’) forms the (first) initiation of a person into a Christian community. The sacrament involves pouring water of the initiate’s head (but full body immersion occurs in (almost) all branches of Christianity) together with the pronouncement of the Trinitarian formula, ‘in the name of the Father, the Son, and the Holy Spirit’. In principle, Christians are baptized once in a lifetime: once you are baptized, you stay baptized. Many Christian denominations recognize one another’s baptisms. So, usually, if you switch from one branch of Christianity to another, you do not need to be ‘re-baptized’. Since baptism creates a ‘permanent sign’, a Christian cannot be ‘un-baptized’, even if an individual no longer identifies as a Christian. All Christians baptize adults, while the majority also baptize children.

The sacrament of baptism is rooted in various biblical stories, notably Jesus’ own baptism (Matthew 3:13-17; Mark 1:9-11; Luke 3:21-23), Jesus’ command to baptize ‘all nations’ (Matthew 28:19), and Jesus’ saying that ‘no one can enter the Kingdom of God unless they are born of water and the Spirit’ (John 3:5). Theologically speaking, baptism unifies the believer with Christ, through which the ‘stain’ of ‘original sin’ is erased, a notion difficult to describe concisely. The idea, very shortly explained, is that because the first two humans – Adam and Eve – disobeyed God’s commandment, all their offspring share both this sin and its consequences, that is, death and earthly suffering. Baptism ‘opens’ the way to a full relationship with God.

Eucharist

The sacrament of the eucharist (Greek: ‘thanksgiving’) is the one probably received the most frequently by Catholics: usually once per week, but daily attendance is not uncommon. Protestants usually celebrate this sacrament less frequently, sometimes even only a couple of times per year. The exact meaning of the sacrament is heavily debated among Christians of the different denominations and confessions.

Three out of the four canonical Gospels (excluding John) connect this sacrament to the biblical story of Jesus celebrating the Jewish Pesach meal (commemorating the liberation of the Israelites from Egyptian captivity) with his friends, the evening before his arrest and subsequent capture and execution by the Romans (Matthew 26:17–30, Mark 14:12–26, Luke 22:7–39, and 1 Corinthians 11:23-26). During this meal, Jesus is reported to have shared the ceremonial bread and wine during the Jewish feast of Pesach, saying: This is my body, this is my blood, eat and drink from it, and continue to do so in memory of me. The eucharist/Last Supper celebrations are a direct response to Jesus’ request.

The interpretation of this sacrament is highly contested among Christians. Roman Catholics and Eastern Orthodox Christians believe that during the celebration the ceremonial bread (host) and wine are changed into the body and blood of Christ (however undetectable by the human senses). Protestants, on the other hand, stress the commemorative elements of the celebration.

Confirmation

Confirmation ‘confirms’ (hence the name) the sacrament of baptism. Especially in cases when an individual received baptism when they were still (very) young, the sacrament of confirmation serves as a public profession of the individual’s faith after his or her coming-of-age. The age of confirmation in the Latin Rite is, somewhat contra-intuitive, between about 12 and 16 years old. It is the only sacrament, together with that of ordination, that has to be administered by a bishop (or his delegate), instead of a priest (all other sacraments) or a deacon (baptism and marriage). Some Protestant denominations also have confirmation, but they do not regard it as a sacrament.

Confirmation is closely connected to the Holy Spirit, the divine helper promised by the risen Christ to his friends. Biblical foundations include: ‘Then Peter and John placed their hands on them, and they received the Holy Spirit’ (Acts 8:14-17) and ‘When Paul placed his hands on them, the Holy Spirit came on them, and they spoke in tongues and prophesied’ (Acts 19:6). The Holy Spirit is considered to be an inspiration for all Christians and is connected to charismata (Greek: ‘things that come out of love’), or ‘gifts’: ‘the word of wisdom, the word of knowledge, faith, the grace of healing, the working of miracles, prophecy, the discerning of spirits, diverse kinds of tongues, and the interpretation of speeches’ (1 Corinthians 12:8-10).

Reconciliation (or confession)

The sacrament of reconciliation, also known as confession or penance, is the first of the two ‘healing’ sacraments. In Christian tradition, sin is understood as something that damages the relationship between a believer, fellow human beings, and God. By confessing sins and receiving absolution (forgiveness) from a priest on behalf of God, this relationship is restored. Catholic teaching distinguishes between everyday (venial) sins and mortal sins. Venial sins weaken the relationship with God but do not destroy it entirely. Mortal sins, on the other hand, break the bond of grace with God and require sincere repentance and absolution to return to a state of grace. Traditionally there are tree mortal sins, idolatry, murder, and adultery, all severing various relationships.

The foundation of this sacrament lies in several biblical passages, including John 20:22-23 and James 5:16. Both speak about Christians being able to forgive one another’s sins. Since the Middle Ages, confession has taken place individually, for example in a confessional booth, but today, ‘penance services’ are also possible for collective reflection and forgiveness. The penitents must have sincere remorse for their sin, a firm resolve not to commit the same sin again, make every effort to compensate for or alleviate the harm caused to others by their sin, and, if applicable, turn themselves in to the civil authorities to face the consequences of their wrongdoing.

Anointing of the sick

The second sacrament in the ‘healing’ category is the anointment of the sick. It is intended for those who are seriously ill, undergoing a dangerous medical procedure, or in the final phase of their life. The sacrament offers spiritual and possibly physical healing and is at the end of one’s life sometimes accompanied by the reception of the eucharist as viaticum (Latin: ‘provision for the journey’). During the anointing, a priest lays hands on the sick person, prays for them, and anoints their forehead (and sometimes also other body parts) with consecrated oil. This ritual is rooted in Scripture, particularly James 5:14-15: ‘Is anyone among you sick? Then he must call for the elders of the Church, and they are to pray over him, anointing him with oil in the name of the Lord.’ While this sacrament was previously seen as the ‘last rites’ or ‘extreme unction,’ it is now applied more broadly and can be received multiple times throughout a person’s life.

Marriage

Marriage is one of the two sacraments of service: it dedicates a man and a woman to a lifelong union in which they support each other and, if applicable, to raise their children in faith and love. The bond of love between the two is symbol of the love between God and humanity in general and between Jesus Christ and his Church specifically. This is also the reason that, in Roman Catholic teaching, a sacramental marriage is, in principle, indissoluble, since God’s love is also unbreakable. However, after the death of a spouse, the widow/widower may remarry.

In many other branches of Christianity, remarriage, however, is possible although sometimes difficult and burdened with social disapproval. Unlike other sacraments, marriage is not administered by a priest but by the spouses themselves, who exchange their vows in the presence of a priest or deacon, and another witness on behalf of the whole Church. Concerning the sacramental marriage between partners of the same sex, different branches of Christianity have different opinions; many Christians are slightly hesitant or outrightly dismissive of same sex sacramental marriage.

Ordination

The sacrament of holy orders (or ordination) is the second sacrament of service, consecrating people to the diaconate (deacon), priesthood (priest), or episcopacy (bishop). This sacrament is conferred solely by a bishop (in the case of the ordination of deacons and priests), who lays hands on the candidate, pronounces the ordination prayer, and anoints the candidate’s hands (only in the case of a priest’s ordination). In the case of the ordination of a bishop, three other bishops are required, who also anoint the candidate’s head.

Ordination is understood as a continuation of Christ’s mission, as expressed in John 20:21: ‘So Jesus said to them again, “Peace be to you; just as the Father has sent Me, I also send you.”’ In the western tradition of the Catholic Church, ordination is reserved for men, and ordained priests are required to remain celibate. The ordination of deacons, however, may also be received by married men (so-called permanent deacons). In other branches of Christianity women may also be ordained and deacons and priests may be allowed to marry (for example in the Old Catholic Church or in the Anglican World Communion).

7. People, pastors, priests, and popes: ecclesial hierarchy

Within the Church’s organization (in every branch of Christianity), there is always a certain kind of hierarchy: in some more than in others. Every branch of Christianity has its own organizational form and ecclesial hierarchy. The Roman Catholic Church differentiates between the common priesthood of all believers, who share in the three munera (Latin: ‘functions’ or ‘duties’) of Jesus Christ, and the ministerial priesthood of those who are specifically ordained as such. The common priesthood means that, in and through the sacrament of baptism, all believers share Christ’s priestly, kingly, and prophetic offices. It is only from within this baptism and this common priesthood that the ministerial priesthood of ordained people can perform its rightful service.

Some traditions, such as the (Roman) Catholic and Eastern Orthodox Churches, have a highly centralized structure with a clear hierarchy of bishops, priests, and deacons, while others, like many Protestant denominations, adopt a more decentralized or congregational model, granting local communities greater autonomy in governance and decision-making. The (Roman) Catholic Church has a very detailed administrative structure:

A parish is the smallest administrative unit of the Roman Catholic Church. It is a globe-spanning network reaching to the far ends of the world. A parish is led by a parish priest, an ordained priest, possibly with the assistance of one or more ordained chaplains, deacons and/or one or more (male or female) pastoral workers, who are fully-trained ecclesial professionals but who are not ordained. Any parish can have one or more churches, chapels, and/or other religious buildings. The typical ‘formal’ dress color for deacons and priest is black with a white collar (so-called ‘clergyman’).

A number of parishes in a given geographical territory form a diocese, headed by a bishop, possibly assisted by one or more auxiliary bishops. The bishop has his ‘own’ church, a cathedral where his ceremonial ‘seat’ (Latin: cathedra) is located. A cathedral is usually bigger, older, and more decorated than a typical parish church (but there are exceptions!) The typical ‘formal’ dress color for bishops is purple.

Some dioceses have more ‘grandeur’ than other, usually for very old historical reasons, and are dubbed ‘archdioceses’. The bishop presiding over an archdiocese is therefore an archbishop. Even though he has more ‘standing’ than his colleagues, every diocesan bishop is an autonomous church leader, only bound to his loyalty to the pope.

A number of dioceses together form a ‘church province’ or ecclesial province, usually along present-day national borders. So, there is a church province of the Netherlands, of Belgium, of France, and so forth. Even though such a province has a chairman – the bishop of one of the dioceses of the province, elected among his colleagues – his job is only to facilitate regular meetings, and he does not have any authority over his colleagues.

A number of Catholic men – almost always bishops – are created cardinals by the pope. These men are considered ‘princes of the Church’ in the sense that they will be the ones gathering in a ‘conclave’ to elect a new pope – usually one from their own ranks – after the passing away of the former one. Their typical ceremonial color is red.

The leader of the worldwide Catholic Church is the pope, who resides in Rome. The pope is, above all, the Bishop of Rome (his cathedral being Saint John Lateran). He is also the head of state of the territorial areas entrusted to the Holy See, known as ‘the Vatican’, located in the heart of Rome, Italy. It is a de jure (by law) and de facto (by fact) independent nation. More than just an earthly ruler – the pope is the spiritual leader of all Catholics all around the world. The pope’s ceremonial color is white.

Bishops and the pope can convene synods (advisory assemblies), while only the pope has the authority to convene a council (a legislative assembly).

The nomenclature surrounding ecclesial titles is illusive to the non-initiated, partly because it varies depending on the branch of Christianity. Terms like ‘priest’, ‘vicar’, ‘pastor’, and ‘minister’ are used by different Christians to denote various types of religious authority figures. Instead of trying to understand all these intrinsic differences, it is best to be very attentive when someone is using these terms and to make sure of what they mean in the specific branch of Christianity you are dealing with.

Many branches of Christianity have their own legal system called ‘Canon Law’, functioning alongside national codes of secular law. In the Roman Catholic Church, canon law serves as the legal system that governs both the ecclesial structure (the Church itself) and the relationships of individuals within it. It encompasses a wide range of issues, from the administration of sacraments to the conduct of those ordained, the structure of dioceses, and the governance of church property. It also deals with matters of discipline, marriage, the ordination of clergy, and the process of the canonization of saints. The Catholic Church’s canon law is organized primarily in the Code of Canon Law, which was first published in 1917 and later revised in 1983.

The Vatican

Even though the Vatican is exclusively connected to the Catholic branch of Christianity, its popularity in the public eye (in films, novels, and books) demands a quick introduction to the world’s smallest independent and universally recognized theocratic state.

The Vatican became independent from Italy in 1929, thanks to the Lateran Treaty between King Victor Emmanuel III, Prime Minister Benito Mussolini, and the pope. It spans an area of 49 hectares and is occupied by less than a thousand citizens. It contains world-renowned buildings like St. Peter’s Basilica, the Sistine Chapel (used for the conclave), the Vatican Apostolic Library, and the Vatican Museums. The Vatican levies no taxes, its economy is sponsored by donations from the faithful worldwide, by the sale of souvenirs, and by museum fees. It has no natural resources, no production facilities, no farms, no airfield or hospital. It does have its own police force, though, known as the Swiss Guard, which guards the premises in general and the pope specifically. For all necessary public facilities, the Vatican cooperates intensely with its neighbor Italy, which surrounds the Vatican on all sides.

The governing body of the Vatican is the Holy See, recognized internationally as a sovereign juridical entity. It has its own network of sending and receiving ambassadors to and from almost all other nations and it has had the status of permanent observer at the United Nations General Assembly since 1964. Four popes have addressed the General Assembly: Paul VI (1965), John Paul II (1979 and 1995), Benedict XVI (2008), and Francis (2015).

The Holy See is administered by the Roman Curia, central institutions taking care of all necessary political work (comparable with ministries in other countries). The Curia consists of the Secretariat of State, several Dicasteries, (formally known as Congregations), legal Tribunals, Pontifical Councils, and Pontifical Commissions. The most famous of these is the Dicastery for the Doctrine of the Faith, formerly known as the Congregation for the Doctrine of Faith, the Holy Office or Supreme Sacred Congregation of the Roman and Universal Inquisition, or ‘just’ Inquisition.

This dicastery oversees the orthodoxy of Roman Catholic theology, Church, and tradition. Its works include, among others, the clarification of theological misunderstandings, the admonishment and, when necessary, the removal of fraudulent bishops, and responding to dubia (‘doubts’) submitted by cardinals. The dicastery was also responsible for the ecclesial disqualification of various high-profile theologians, such as Hans Küng, Leonardo Boff (1938), and Jon Sobrino (1938).

Different church buildings

Catholics use various words for their church buildings, depending on a variety of circumstances and considerations. Four are the most important to know: (1) chapel, (2) church, (3) cathedral, and (4) basilica. A chapel is a smaller place of worship. For example, the Sistine Chapel in Vatican City, where the papal conclave is held. A church is the general term for places of worship, but usually, as in parish church, it refers to a building in which a local congregation gathers. A cathedral is a church that contains the cathedra (Latin: ‘seat’) of the local bishop, and therefore functions as a central church in a diocese. A basilica is an honorary title that can be given to any church building by way of papal recognition. This worldwide network of basilicas symbolizes the connection between the world Church and the Bishop of Rome.

8. Nuns, monks, and mysticism: the monastic tradition

Christian monasticism has its roots in the 3rd and 4th century, when individual men and women started to go into the deserts of Syria and Egypt to live a life of solitude, poverty, and contemplation. These individual hermits started to attract followers relatively quickly, and they organized their life around the person and spirituality of the ‘father’ or ‘mother’ of their particular choice. The wisdom of these Desert Fathers and Mothers, like Anthony the Great, Pachomius, Onesima (or Isidora), AND Syncletica of Alexandria, became well known through various compilations of stories and quotes, and remains so up and until our present day.

Out of these individual Desert Mothers and Fathers and their followers, the first monastic orders we recognize as such developed. These were especially those of Augustine of Hippo and Benedict of Nursia, who gave their names to the ‘Rules’ on which individual religious communities (the Augustinians and Benedictines respectively) were established throughout Europe and North Africa. These monastic Rules organize the spiritual and practical lives of monks and nuns who voluntarily surrender to these regulations. Their lives are based on the vows of poverty, chastity, and obedience. Later, other orders emerged, like the Franciscans (founded by Francis of Assisi), the Dominicans (founded by Dominicus de Guzman), and the Jesuits (founded by Ignatius of Loyola), to name just a few.

Generally speaking, these monastic organizations can come in the form of an order, a congregation, or a society; the former are usually older, while the latter two tend to have been founded much later in history. These organizations can be contemplative or active in nature. Contemplative orders focus primarily on prayer, silence, and monastic life within the confines of a monastery, dedicating themselves to God primarily through solitude and liturgy. For example, the Benedictines, Carmelites, Capuchins, and Carthusians. Active congregations, by contrast, combine prayer with apostolic works such as education, healthcare, or social service, outside the walls of their monastery, and going into the world. For example, Dominicans and Franciscans. Monastic communities are usually either all-male or all-female; however, some hybrid forms do exist, called ‘double-monasteries’.

The buildings monastics live in are called ‘monasteries’, but sometimes the word ‘convent’ is also used. The word ‘abbey’ is used for contemplative monasteries. Female monastics are called ‘nuns’ or ‘sisters’ in contemplative orders, and ‘sisters’ in active ones (or as a general reference for all female monastics). Male monastics are called ‘monks’ or ‘brother’ (again in the context of contemplative orders) and ‘brothers/friars’ (in active ones). Within a monastic context, the word ‘padre’ (Latin: pater, ‘father’) is reserved for male monastics who have been ordained a priest to serve their community and their mission as such. Contemplative orders have more or less sovereign monasteries, headed by an abbot or an abbess. Active congregations (and societies) are more globally organized: every monastery has its own local superior, while having per country or region a Provincial Superior, and worldwide a Superior General who has overall responsibility.

Scheme #4 – A schematic overview of various monastic and religious movements.

| Order | Congregation | Society
| Contemplative | Active | Active | Active
Foundation | Older | Newer
Monasteries | Abbey | Convent | Convent | House
Titles | Monk/Nun Brother/Sister | Brother/Sister | Brother/Sister | Brother/Sister
Governance | Abbot/Abbess | Superior | Superior | Superior

The relation between a local monastery of a certain order or congregation and the local ‘secular clergy’ (ordained men, not being monastics), especially the bishop, is interesting and sometimes complicated. The reason is that both are independent of one another, creating something like a double hierarchy within the Roman Catholic Church. Most of the orders, congregations, and societies are ‘exempt’: they do not fall under the jurisdiction of a bishop.

The monastic tradition also maintains the concept and practice of ‘choral prayer’, collective prayers, spoken or sung, sometimes by individual monastics, but usually with the whole monastery or convent. Contemplative orders usually have more time and practice with this kind of prayer, while active ones have less, because of their work in the world outside the walls of the monastery. The ‘Liturgy of the Hours’ or ‘Divine Office’ as it is also called, has a maximum of seven prayer moments per day: Matins (prayers in the night or very early morning), Lauds (morning prayers), Terce (prayers before noon), Sext (prayers at noon), None (prayers after noon), Vespers (evening prayers), and Compline (prayers before bedtime).

And last but not least, monastic tradition is linked, although not exclusively, with the concept of ‘mysticism’, which is an important part of the monastic life’s continuous attraction, also for non-Catholics or non-Christians. Mysticism – mystical experiences and the religious reflection on those experiences – is the subject of continuous theological discussion: to define it appears to be very difficult. It has to do with the individual experience of people with ‘the divine’, a close connection between the individual soul seeking God and God itself. Some mystics have many of these experiences in their lifetime, while others have to make do with just one single instance.

Major figures in the Catholic mystical tradition include Hildegard of Bingen, Hadewijch of Brabant (13th century), Angela of Foligno (1248-1309), Catherine of Siena, Juliana of Norwich, Teresa of Avila, John of the Cross (1542-1591), Thérèse of Lisieux (1873-1897), Elizabeth of the Trinity (1880-1906), and Thomas Merton (1915-1968).

9. The ‘bonum commune’: social teachings

In 1891, Pope Leo XIII published his encyclical Rerum novarum (Latin: ‘About new questions’), kicking off what would later be known as the Social Teaching of the Roman Catholic Church. It addresses laborers’ conditions, their rights, the regulation of private property, and the role of the ‘modern’ state. It was the first time that the Roman Catholic Church addressed these ‘new questions’ on this ecclesial level, pressed to do to for numerous reasons: (1) the rapid rate of industrialization across Europe in the 19th century, including urbanization, the exploitation of laborers, their poor housing, and the loss of traditional communities and guild structures; (2) the rise of socialism, communism, and liberal capitalism in Europe (and abroad) as competing systems of meaning-making, often directly opposed to the traditional values of Christianity and Roman Catholicism; (3) and the decline of the so-called Societas perfecta model through which the Roman Catholic Church saw itself as a self-sufficient and independent state, the loss of the Papal States, and the idea of separation of Church and state. Pope Leo sought to reclaim some of the authority lost amid the Church’s relative political marginalization by addressing pressing questions about social injustice in the world at large.

After Leo XIII, the Church’s social teaching was furthered by other famous encyclicals. In Quadragesimo anno (’40 years after’ Rerum novarum, 1931), Pius XI wrote about the principle of subsidiarity, criticizing both socialism and unrestrained capitalism. John XIII updated the Roman Catholic teachings in the light of post-war political realities, emphasizing global solidarity (in Mater et magistra, ‘Mother and Teacher’, 1961). His next encyclical, Pacem in terris (‘Peace on Earth’, 1963), addressed all the peoples of the world (a novelty), focusing on peace, human rights, and international order. The Second Vatican Council codified these teachings in Gaudium et spes (‘Faith and Hope’, 1965) and in Dignitatis humanae. This was continued by Paul VI, in Populorum progressio (‘On the Progression of the Peoples’, 1967); and by John Paul II, in Laborem exercens (‘Exercising Work’, 1981), in Sollicitudo rei socialis (‘Concern for Social Issues’, 1987), and Centesimus annus (‘100 years’ after Rerum novarum, 1991), reflecting on the fall of communism and the apparent victory of (American) capitalism. Benedict XVI addressed themes of globalization, economy, and ecology in Caritas in veritate (‘Charity in Truth’, 2009). Pope Francis focused heavily on ecology and the connection between social injustice, the refugee crisis, and global climate change in Laudato si’ (‘Praise be you’, a reference to Saint Francis of Assisi’s Canticle of the Sun, 2015) and Fratelli tutti (‘All Brothers’, 2020).

The social teaching of the Roman Catholic tradition is based on four principles (even though sometimes others are mentioned): (1) human dignity, (2) the common good, (3) subsidiarity, and (4) solidarity. To start with the first one, this means that everybody is entitled to some basic human rights, not because of their race, social class, country of birth, and such things, but because they simply exist. This principle is the ground on which all other elements of Catholic Social Teaching stand, insisting that social, economic, and political systems must respect and protect the fundamental rights of all people. The Universal Declaration of Human Rights of 1948 is its secular pendant.

Secondly, the idea of the ‘common good’ (Latin: bonum commune) balances the idea of collective and individual rights. Gaudium et spes (1965) defines bonum commune as ‘the sum total of social conditions which allow people, either as groups or as individuals, to reach their fulfilment more fully and more easily’ (paragraph 26). To put it more plainly, this refers to the deeply Christian notion that people exist (factually and ideologically) only with and for others. No person is an island: humans are social creatures. In Laudato si’, Pope Francis expanded the notion of bonum commune also to ‘integral ecology’, the idea that humanity as a collective is responsible for the care for ‘our common home’.

Thirdly, subsidiarity is the idea that (political) decisions should be handled on the lowest possible level, the closest to the people who will be influenced by these decisions. Higher authorities should only be involved when necessary for the benefit of the lower echelons. This is applicable to commercial organizations, charities, nations, and the church organization itself.

Fourthly, the idea of solidarity calls for a global vision of humanity in which everyone is treated with respect, justice, and compassion, and where individuals and communities work together to build a more just and peaceful world. Of special interest is the commitment to the poor, the marginalized, and the vulnerable. All humans are part of one human family, streaming from one source (God) and sharing a common destiny (God again).

10. The Golden Rule: moral thinking

Christian ethics are primarily based on ideas of natural law and conscience, and on several key passages from the Old and New Testament, especially the Ten Commandments. The theological discussion about the first two elements is very difficult to summarize in a few sentences. Especially the meaning of the notion of ‘nature’ varies significantly for different people in different time periods. Sufficient here is to say that ‘natural law’ in its common Christian iteration is believed to be inscribed in creation and discernible through rational reflection, while conscience is the inner voice through which individuals apply this law to concrete situations, enabling them to judge what is right and wrong. Very simply put, most Christians believe that the distinction between good and bad is universal – the same for all people of all ages and of all places – and understandable for everybody, without the need of divine revelation.

Biblical foundations

This does not mean that Christians neglect the Bible as a finding place for ethical guidelines. The Ten Commandments have a very important place in Christian morality, being among the most well-known and influential passages from the Old Testament, and having influenced Jewish and Christian politics, ethics, and art since they were written down. The Ten Commandments are often seen as an explication of the ‘natural law’.

However, the Bible would not be the Bible if there were not two versions of the Ten Commandments to be found in it, one in Exodus 20:1-17 and one in Deuteronomy 5:4-21. And Christianity would not be Christianity proper if several denominations did not have different sequences and variations, complicating matters even more. But casting all these differences and nuances aside, ‘the’ Ten Commandments are thought to have been dictated by God to the prophet Moses on the summit of a mountain, when the Israelites were traveling from Egypt to the Promised Land. These commandments were inscribed on two stone tablets, which were placed in the Ark of the Covenant, a richly decorated box that was eventually brought to the Temple in Jerusalem, where after some time it disappeared from the Bible and from history.

The ten are divided into two parts: the first three concern the relation between humans and God and the other seven concern the relation between humans themselves. This last set of seven is divided into one positive commandment (to honor one’s parents), and six negative ones (‘you shall not…’). Furthermore, the first four of the negative commandments are about acting, while the last two are about desiring (even without acting the desire out).

‘The Lord is your God. You shall have no strange gods before him’. The prohibition to worship any other divinity than God itself is a core tenant of all monotheistic religions, including Christianity in all its denominations.

‘You shall not take the name of the Lord your God in vain.’ Traditionally interpretated as a prohibition to curse (and swear) in God’s name, since God is too holy to be misused in human disagreements. Speaking falsely about God is also prohibited by this commandment.

‘Keep the Sabbath holy.’ The Sabbath (or Saturday) is the seventh day of the week, a day that is set apart from all other days (thus ‘holy’), to rest from work and concentrate on God. In Christian tradition, the Sunday has become the most holy day of Christians, usually dedicated to faith, Church, and family.

‘Honor your father and mother.’

‘You shall not (unlawfully) kill.’ There is discussion whether this commandment should be interpreted as a prohibition of all killing (including the death penalty) or ‘only’ of murder.

‘You shall not commit adultery.’ In Christian moral thinking adultery has come to denote all sexual sins and deprivations and not only being unfaithful to one’s spouse.

‘You shall not bear false witness against your neighbor.’ Speaking untruthfully or lying to or about anyone or anything is covered by this prohibition.

‘You shall not desire your neighbor’s wife.’ As stated earlier, the last two commandments are not so much about doing something wrong but about desiring something that is not yours to have. Of course, this prohibition has come to include women who desire their neighbor’s husband.

‘You shall not desire your neighbor’s goods.’

In the New Testament, Jesus summarizes the Ten Commandments in two expressions. The first is the so-called ‘Twofold Commandment of Love’ or the ‘Great Commandment’ (Matthew 22:35-40; Mark 12:28-31; Luke 10:25-28; see also John 13:34; 15:12). In all three accounts, we find a discussion between a person and Jesus, the first asking the latter to define which commandment is the greatest. Jesus (or in Luke’s version the other person) answers with a quote from Deuteronomy (6:4-5): ‘You shall love the Lord your God with all your heart, and with all your soul, and with all your might;’ only to then add another quotation, now from Leviticus (1:18): ‘You shall love your neighbor as yourself’. The three Gospel accounts agree that Jesus positions love towards God and love towards one another as the greatest commandments per se and that both commandments are equally valuable: loving God means loving your neighbor, and vice versa.

The second addition is the ‘Golden Rule’. Jesus proclaims to his followers: ‘In everything, therefore, treat people the same way you want them to treat you, for this is the Law and the Prophets’ (Matthew 7:12). Or in a shorter version: ‘Treat people the same way you want them to treat you’ (Luke 6:31; see also Tobit 4:15). One could argue that ‘love’ is indeed the cornerstone of Christian faith and morality, even though individual Christians frequently have struggled implementing this imperative in their everyday life.

Virtues and sins

In Christian tradition, the concept of virtues is very important in the context of morality. A virtue is a stable disposition or a habit towards something good. A virtuous person consistently wants what is good for others and acts upon that intention. In the tradition, various listings of virtues have been compiled and promoted, some of them getting quite some attention and influence in culture and art.

We have, for example, the theological virtues, so called because they are directly connected to God: fides (‘faith’), spes (‘hope’), and caritas (‘charity’ or ‘love’). In the Letter to the Corinthians 13:13, Paul speaks about these three as the greatest gifts to humankind, even though love is the greatest of them all: ‘But now faith, hope, and love remain, these three; but the greatest of these is love.’ Another famous set of virtues are the cardinal virtues, called this because it is on these four that the other virtues ‘hinge’ (Latin cardo): prudentia (‘prudence’), iustitia (‘justice’), fortitudo (‘strength’), and temperantia (‘temperance’).

Theses three-plus-four virtues have acquired their dark pendants in the form of the so-called seven capital sins (Latin: caput, ‘head’): a kind of categorization of all vices and malice humankind is capable of. They are immortalized in paintings, plays, novels, films, and games. Of course, there are variations in the list, but these are the most commonly used: ira (‘wrath’ or ‘anger’), avaritia (‘greed’), acedia (‘sloth’), superbia (‘pride’), luxuria (‘lust’), invidia (‘envy’), and gula (‘gluttony’).

These capital sins are also known as the ‘seven deadly sins’, a name that is somewhat confusing, since many Christians distinguish between ‘mortal’ and ‘venial’ sins. Mortal sins are of the severest category and are said to destroy one’s relationship with God, while venial ones are considered less of a threat. In the case of mortal sin, the matter at hand must be grave in nature, must be committed with full knowledge of the sinfulness and gravity of the offense, and must be committed with deliberate and complete consent.

11. Intercessions: Mary and the saints

In this one-to-last chapter, we have to discuss some particularities that are connected to (Roman) Catholicism and Eastern Orthodoxy (but mostly absent in Protestantism): saints and the figure of Mother Mary, relics, miracles, rosaries, pilgrimages, and icons. Even though they may not be at the religious or theological heart of Christianity – sometimes even shunned by other denominations – they nevertheless play an important role in the lives of individual believers and in the reception of Christianity in the outside world.

Saints

To start with the notion of sainthood and beatification, both the Roman and Eastern Catholic as well as the Eastern Orthodox traditions have myriads of saintly figures, historical and legendary. Their statues and icons turn up in churches and chapels, where the faithful gather around them to pray and burn candles, all in the hope of getting the saint to intercede (mediate) on their behalf, or to thank them if they already have. The saints are not believed to intervene themselves, but to ‘deliver’ the prayers and needs of the faithful to God, who can or cannot intervene concretely. Famous saints include Mother Mary, the Apostles Peter and Paul, Francis of Assisi, Teresa of Avila, and Mother Teresa of Calcutta (1910-1997).

Parishes are named after them, as well as schools, hospitals, and orphanages, in a system known as patronage. Every conceivable occupation, natural phenomenon, and problem has its own patron saint or saints. To give some examples, Joseph (Mary’s spouse) is the patron of workers, Scholastica (twin sister of Benedict of Nursia, founder of the Benedictine Order) is for protection against storms, Jude Thaddeus for ‘desperate causes’, and Nicholas of Myra (known as Sinterklaas in the Netherlands) is the patron of sailors, merchants, pharmacists, brewers, students, and prostitutes. Every church, town, region, and country may have ‘favorite’ saints, shifting in popularity as time goes by.

The idea of sainthood is rooted in the theological notion of the communio sanctorum (Latin: ‘the community of saints’). These saints are all people who have believed in Christ (and have passed away), those who are living now in Christ, and those who will believe in Christ in the future. This community of saints denotes an interconnectedness transcending the barriers of time and place. The title ‘saint’ for every individual believer is, of course, more a vocation to be worked hard upon, than a descriptive term per se. This interconnectedness makes it possible for people to call upon those who have already passed away – who are believed to be with God in heaven – to intercede on their behalf. Saints function as exemplary figures along whose lives the individual believer can mold their own, and as inspirations to make concrete one’s call to sainthood.

The idea of saints being intercessors for individuals’ prayers to God expresses the idea of solidarity among the believers. As believers can pray to God on behalf of one another in this earthly life, then the saints in heaven can pray for the living.

Canonization

The title ‘saint’ can be used to describe all the believers on earth and in heaven collectively. In a more restricted way, it is only used for the latter. And in an even more restricted way, ‘saint’ applies to those people who have been recognized as such by the Catholic Church. The Catholic Church has a whole procedure for the declaration of sainthood (canonization). Of course, the Church does not ‘make’ saints out of thin air but recognizes what is believed to have already been established by God. The process of canonization starts at the level of the diocese that the candidate-saint originates from or has a special connection to. If satisfactory, the dossier is handed over to the Vatican Dicastery for the Causes of the Saints. Based on the dicastery’s advice, the pope can decide to declare a person ‘venerable’, ‘blessed’ (Latin: beatus) by beatification, or saint (Latin: sanctus) by sanctification or canonization. To be declared beatus or sanctus, one or more miracles have to be attributed to the candidate’s intercession.

Mary: mother of Jesus, Mother of God

Within this ‘system’ of saints, Mary the mother of Jesus holds a very important place – again in both Catholicism and Eastern Orthodoxy. There is an entire subsection of theology dedicated to her – Mariology – but sufficient for now is to say that her motherhood of Jesus positions her as the highest-ranking saint in all of Christian history. In Catholicism and Eastern Orthodoxy, Mary bears the theologically challenging title ‘Mother of God’ – in Chalcedonian Christianity the ‘bearer of God’ (Greek: theotokos) – and is held to be a perpetual virgin, to have been born without original sin (called the ‘immaculate conception’), and to have been assumed into heaven with body and soul. Tied to the very widely spread veneration of Mary is the concept of Marian apparitions, notably to Juan Diego and Juan Bernardino in Tepeyac, Mexico (1531), to Bernadette Soubirous in Lourdes, France (1858), to Lucia, Jacintha, and Francisco in Fatima, Portugal (1917), and to Mariette Beco in Banneux, Belgium (1933).

Recognition

For the official ecclesial recognition of both miracles necessary to attain sainthood and for apparitions of Mary, the Catholic Church has to establish whether these phenomena are caused by God (through the saints/Mary) or by natural causes. Because of modern science, the Catholic Church has become more hesitant to establish such a ‘transcendent’ cause: what was thought of as a true miracle in the 19th century can sometimes be easily explained by contemporary science. On the other hand, the Church wishes to have a certain ‘control’ over official saintly miracles and apparitions because of the danger of fraud, manipulation, or misconceptions. The verdict can vary from nihil obstat (Latin: ‘nothing hinders’), when a miracle or apparition may be ‘safely’ considered having to do with God, to declaratio de non supernaturalitate (‘declaration of non-supernaturality’), basically disqualifying the miracle or apparition as not of supernatural origin.

Relics

Connected to this whole issue is the matter of relics, objects regarded as holy in the Catholic and Eastern Orthodox traditions. We have three ‘classes’ of relics. The first class concerns objects that are associated with Jesus’ life, like splinters of the Cross or pieces of the Crown of Thorns, or – somewhat puzzling for modern sensibilities – with the physical remains of people martyred for their faith or declared a saint, like bone fragments, hair, or nails. The second class, much better to digest from the perspective of the 21st century, involves objects frequently used by the saints, like clothes, bed linen, handkerchiefs, or rosaries. The third class of relics concerns objects that have been in contact with those of the first two classes. The spiritual goal of relics is to bring the faithful closer to the ‘living’ testimony of the Christian faith.

Miscellaneous issues

At the heart of popular devotion lie some miscellaneous objects and practices that deserve their own mention, however short.

Rosary: a devotional prayer that involves the meditative recitation of (predominantly) the ‘Hail Mary’, while reflecting on key events (called ‘mysteries’) in the lives of Jesus Christ and Mary, using a string of beads to guide the sequence.

Medallions: small, often blessed, religious objects, typically worn as necklaces or somewhere else on one’s body, that depict Jesus Christ, Mary, or the saints, and serving as tangible signs of faith, protection, and devotion.

Ex-votos: devotional offerings, such as plaques, paintings, or objects, left in churches or shrines dedicated to a saint or Mary in gratitude for divine help, healing, or answered prayers.

Stigmata: bodily marks, wounds, or sensations of pain that correspond to the crucifixion wounds of Jesus Christ, experienced by certain mystics or saints as a sign of deep union with Christ’s suffering.

Icons: popular in the Eastern Orthodox tradition, but increasingly also in other Christian confessions, notably Catholic traditions; an icon depicts Jesus, Mary, or one or more saints. In Eastern Orthodox traditions, the icons function as a kind of ‘sacramentals’ to help the faithful get in touch with the divine world.

12. Painful dossiers: what also happened

Of course, the sun does not always shine in the realm of Christianity: the history of Christendom is littered with triumphs of piety, charity, and scientific discoveries, but also with painful and embarrassing dossiers and issues, which still linger beyond the veil of ideal Christian love. Unfortunately, no introduction to any Christian tradition is complete without also addressing these painful dossiers. Since there are – again unfortunately many – examples of Christian individuals and institutions failing to live up to Christ’s example, some are inescapable: androcentrism, crusades, antisemitism, inquisition, colonialism, and sexual abuse in pastoral relationships.

Androcentrism: when men rule

Christian tradition, in all its countless manifestations, denominations, and historical branches, has been deeply embedded in the broader cultural fabric of Western civilization. From its early development in the Roman Empire to its shaping role in medieval Christendom and its continued influence in contemporary societies, Christianity has both shaped and been shaped by the dominant cultural, political, and philosophical frameworks of the West. This includes the particular cultural configurations of Europe and North America, which, like most other non-Western cultures, have historically been marked by an uncritical androcentric (male-centered), cisgender, and heteronormative worldview that marginalizes or excludes female or queer persons, and people with various sexual orientations.

In response to these dynamics, critical theological movements have emerged that seek to challenge and transform traditional modes of theological thought and ecclesial praxis. Liberation theology, from the context of Latin America, aimed for social justice in the late twentieth century, foregrounding the experiences of the poor and oppressed, and has advocated for a preferential option for the poor or marginalized. Building on the insights of liberation theology, feminist theologians, like Mary Daly (1928-2010), Rosemary Radford Ruether), and Phyllis Trible (1932), became a critical voice within Christianity challenging stereotypical thinking at large. Feminist theologians recovered neglected female figures in the biblical tradition and church history, and reimagined theological language and imagery to reflect women’s experiences and agency. Similarly, queer theology – think for example of Gerard Loughlin, Marcella Althaus-Reid (1952-2009), and Kathy Rudy (1956) – has arisen to contest the heteronormative assumptions that have shaped much of Christian theology and ethics. Drawing on queer theory, these approaches challenge fixed categories of gender and sexuality, critique the exclusion of LGBTQ+ persons from ecclesial life, and offer alternative readings of biblical texts that resist normativity and create space for diverse identities.

Christian denominations and individual communities are still in the process of figuring out what these insights might concretely mean for them. More liberal Christians try to embrace them to at least some degree, while more conservative Christians are hesitant to accept them (or actively combat them), often perceiving these as departures from biblical authority, theological orthodoxy, ecclesial tradition, or the moral order believed to be divinely instituted.

Crusades: how to kill an infidel

The Crusades are also a theme of controversy, inside and outside Christendom. The expression ‘being on a crusade’ has outlived its original medieval context and typically implies that someone is pursuing one’s goals with excessive zeal, self-righteousness, and ideological rigidity.

Originally, the Crusades were a series of military campaigns, sanctioned by popes and other ecclesial leaders, led by Western Christian nobles, ranging in numbers I (1096-1099) through VIII (1270). The initial aim of the early Crusades was to “liberate” Jerusalem and the other places associated with the life of Jesus Christ in the Holy Land (Israel/Palestina), then under Muslim control. They succeeded and established the Latin Kingdom of Jerusalem until the recapturing by Muslim forces under Saladin in 1187, following the Battle of Hattin. When Acre fell in 1291, the last Crusaders left the Holy Land, never to return. Other (and later) Crusades were aimed at targets in Europe itself, especially against the Islamic Caliphate in Iberia and against the Cathars in the South of France (1209-1229), who happened to follow their own, distinct version of Christianity.

The Crusaders – usually the less entitled nobles and a great number of peasants, craftsmen, and low-level knights – most definitely had a spiritual goal with their endeavor. Pope Urban II promised the participants of the First Crusade a full remission of sins, a promise repeated by other popes for the next Crusades too. Participation was understood as a kind of pilgrimage, but armed to the teeth. The protection of Christian pilgrims traveling to the holy places was a genuine goal too. However, political and economic motives also played important roles. For nobles and knights, the Crusades presented opportunities for land acquisition, wealth, and social status. Besides, for many rulers the Crusades were a great chance to rid themselves of restless wandering warriors, who otherwise would pester, bully, or violate the local populations in the countries or their origin.

The Crusades were also marked by significant acts of grotesque violence, not only against Muslim forces in the Holy Land but also against other groups and communities the crusaders encountered. Crusaders massacred thousands of Muslims during the capture of cities like Jerusalem in 1099. They also turned against fellow Christians, most notably during the Fourth Crusade (1204), which resulted in the brutal sack of Constantinople (a city under the rule of Christian emperors), and against Jews, with pogroms in the Rhineland during the First Crusade (1096), where entire Jewish communities were massacred.

In right-wing extremist circles, Crusade symbolism is sometimes appropriated to justify violence against Jews and Muslims.

Antisemitism: blood libel

As touched upon several times already in this book, Christendom has fallen to outbursts of antisemitism frequently throughout its two thousand years of history. Jews were regularly abused, exiled, or even murdered because of their faith and ethnicity (called ‘pogroms’). Jews were regularly forced to live in ghettos and to wear special insignias revealing their identity to everybody. Unfortunately, many Christians had forgotten that their Lord and Savior himself was a devout Jew, just as his family and circle of friends and followers were. It was the Second Vatican Council’s Nostra aetate (Latin: ‘In our time’) that formally rejected these antisemitic notions and ideas in 1965.

The most common Christian accusation against the Jews was that of deicide (Greek: ‘God murder’), the idea that all Jews collectively – both past, present, and future – were personally responsible for the death of Jesus Christ, even though the Gospels themselves show that the implementation of the crucifixion was exclusively in Roman and not in Jewish hands. The idea that all Jews were responsible, not just the ones who handed Jesus over to the Romans, lies in the interpretation of a very famous verse in the Gospel of Matthew (27:25): ‘May his blood be on us and on our children.’ Another common accusation was that of the so-called ‘blood libel myth’, the false idea that Jews would kidnap and kill Christian children to use their blood in the preparation of the matzah, the unleavened bread eaten during their Feast of Pesach.

In modern times, this antisemitism has contributed to modern ‘Zionist’ conspiracy theories.

Inquisition: judging high and low

Besides the Crusades, no other Christian institution has generated so many cultural myths as the Inquisition. In reality, the Inquisition was not a single, monolithic body but a diverse set of ecclesial tribunals that emerged within the Catholic Church from the 13th century onward. Their primary task was to develop legal procedures for identifying, trying, and correcting offences against fides et mores (Latin: ‘faith and morality’): not only – as modern minds tend to remember – heresy, blasphemy, apostasy, and (later) witchcraft, but also (and primarily) matters of ecclesiastical discipline, clerical conduct, and moral transgressions. Ecclesiastical judges could impose penances and sanctions, while the execution of corporal or capital punishment, where applicable, was handed over to local secular authorities.

Different regions created their own Inquisitions to address specific pastoral and social concerns. Far from serving only ideological purposes, these tribunals often performed stabilizing functions within communities by offering formal legal procedures at a time when public justice could easily devolve into mob violence. Paradoxically, the very structure of inquisitorial law – its reliance on written evidence, regulated procedures, and opportunities for defense – often afforded the accused a more predictable and less arbitrary process than they might otherwise have received.

The Spanish Inquisition, established in 1478, became the most notorious largely due to its political entanglements and the powerful anti-Spanish propaganda that circulated in England and the Low Countries during the 16th century. Its mandate extended over both the Iberian Peninsula and Spain’s overseas territories. The Roman Inquisition, created in 1542 by Pope Paul III, focused on safeguarding doctrinal integrity and ecclesial discipline within the Papal States. Over time it evolved into the Supreme Sacred Congregation of the Holy Office in 1908, the Congregation for the Doctrine of the Faith in 1965, and in 2022 the Dicastery for the Doctrine of the Faith.

The legacy of the various Inquisitions is therefore complex. While episodes of torture and severe punishment occurred, most cases did not result in execution; many concluded with non-lethal penances, acquittals, or pastoral admonitions. Moreover, the widespread witch persecutions of the 16th and 17th centuries, especially in the politically fragmented German territories, took place largely outside the jurisdiction of the Inquisition. Although modern imagination often equates the Inquisition with the worst forms of religious coercion, a more nuanced historical view recognizes both its problematic aspects and its role as a legal institution that, at many times and in many places, sought to impose order, ensure due process, and regulate the life of everyday people and nobles alike.

Colonialism: the marriage of Church and politics

The relationship between Christian Churches and political power evolved from marginal to deeply entangled. In its earliest centuries, Christianity existed as a (persecuted) minority within the Roman Empire, but with the Edict of Milan (313) and the rise of Emperor Constantine, the Church became a formal partner of imperial authority. This inaugurated a long-standing alliance between throne and altar, in which spiritual and secular powers reinforced one another: rulers supported ecclesial expansion, while the Church conferred divine legitimacy upon political authority.

From the late Middle Ages onward, the development of seafaring and the emergence of global trade enabled European powers to extend this Church-state partnership far beyond the European continent. The first wave of colonial expansion, led by Portugal along the African coasts and by Spain in the Americas, was shaped by theological as well as political motivations. The Treaty of Tordesillas (1494) divided the non-European world between these two Catholic monarchies (Spain and Portugal), framing territorial claims in explicitly religious terms. Within this context, missionaries – initially Roman Catholic, later also Protestant – accompanied explorers, soldiers, and traders, becoming integral to these enterprises. Commercial actors such as the Dutch East India Company or the Hudson’s Bay Company further intensified the entanglement of religious, political, and economic interests, as evangelization and imperial expansion were often presented as mutually reinforcing goals.

These developments also triggered fierce debates within Europe about the moral and theological status of the peoples encountered. Thinkers such as Bartolomé de Las Casas (1484-1566) and Juan Ginés de Sepúlveda (1490-1573) argued over whether non-Christians in the newly ‘discovered’ regions were fully human and therefore deserving of rights and protections (or not). Such discussions underscored how deeply the colonial project intertwined Christian anthropology with imperial ambitions. A second major wave of expansion followed in the 19th century. After the Berlin Conference (1884-1885), the so-called ‘Scramble for Africa’ accelerated the division of the continent among European powers. Here too, Churches, Roman Catholic and Protestant alike, operated within a broader matrix of political and commercial interests, often legitimizing imperial control through narratives of civilizing and Christianizing missions. Only with the Enlightenment, and later the rise of secularism (democratized in the second half of the 20th century), did these long-standing entanglements begin to be fundamentally questioned. The traditional authority of the Churches was challenged by emerging concepts of individual rights, religious pluralism, and the separation of Church and state.

Christian missionaries were both agents of European colonial expansion and advocates for social justice within colonial systems. Missionaries frequently accompanied colonial expeditions, contributing to the suppression of local religions, customs, and languages. Yet their presence was also instrumental in building institutions that served the local population: schools, hospitals, orphanages, and libraries. In many parts of the Global South, Christian missions laid the foundations for literacy, public health, and social welfare, particularly in areas neglected by colonial administrations themselves. This double legacy makes the historical role of missionaries rather ambivalent, also in the former colonial territories. Later, in the 20th century, liberation theologians would draw from this prophetic tradition to denounce neocolonial economical structures and to reimagine the Church’s mission as solidarity with the oppressed.

Sexual abuse: institutional blindness

Over the past decades, revelations of sexual and other forms of power abuse within pastoral relationships in Christian ecclesial contexts, most visibly within the Roman Catholic Church, have sparked stark moral, pastoral, and institutional crises. While abuse occurred in multiple denominations, the Catholic Church has been especially scrutinized due to the scale of the revelations, the hierarchical nature of its governance, and patterns of systemic cover-ups. Initial reports in the United States, Ireland, and Australia in the 1990s and early 2000s unveiled not only abuse by clergy, but also longstanding efforts by bishops and other religious leaders to shield perpetrators and silence victims. The crisis has since become global, with inquiries uncovering abuse in Latin America, Africa, Asia, and continental Europe. The Church’s delayed response – often prioritizing institutional reputation over justice for victims/survivors – has deeply damaged its moral credibility in the eyes of its own faithful as well as in those of the larger public. Papal initiatives, including the establishment of safeguarding commissions and legal reforms under Pope Benedict XVI and Pope Francis, signal a shift toward accountability. Yet the crisis has exposed deeper issues around power (abuse), sexuality, and clericalism.

Zooming in on the Netherlands and Belgium, the exposure of clerical sexual abuse has deeply impacted public trust in the Christian Churches in general and the Roman Catholic Church specifically, and prompted both ecclesial and governmental inquiries. In Belgium, the independent Halsberghe Commission, tasked with investigating abuse cases, received hundreds of testimonies and reported structural failings in the Church’s handling of complaints. In the Netherlands, the 2011 report of the Deetman Commission revealed that tens of thousands of minors had likely suffered abuse in Catholic institutions between 1945 and 2010, ranging from boarding schools, to seminaries and orphanages. Both reports highlighted not only the abuse itself, but also a pervasive culture of silence, deference to authority, and lack of oversight. These findings led to compensation schemes, apologies by church leaders, and internal reforms, yet survivors and critics continue to question the adequacy and sincerity of the Church’s response. Theologically, the crisis has forced a painful reckoning with the gap between proclaimed values and institutional practice, raising fundamental questions about vulnerability, clerical accountability, and the need for an ecclesial practice grounded in transparency, justice, and healing.

Part II: 101 Catholic theology

To compose an introduction into Catholic theology is first and foremost a question of divisions: every theologian has their own, complete with elaborate argumentation. What I have tried to do, is to list the most important ‘tracts’ of the classic Christian theological tradition, which will introduce the theologian-to-be to the major ‘chapters’, notions, and ideas discussed in (academic) Christian theology. The divisions I have chosen, are as follows:

In Christian tradition God reveals itself as Creator (Chapter 3), as Savior (Chapter 4), and Whole-Maker (Chapter 5), or more traditionally phrased as Father, Son, and Holy Spirit – the so-called ‘economic Trinity’.

The conundrum of three divine persons still being one godhead is discussed in the context of the so-called ‘immanent Trinity’ (Chapter 2).

Next are the problem of evil (Chapter 6), human nature (Chapter 7), sacraments (Chapter 8), the Church (Chapter 9), and the eschaton or end-of-the-world (Chapter 12).

In between we have a twofold discussion on the theological appraisal of the existence of other religions (Chapter 10) and of non-Christian cultural contexts (Chapter 11).

Before all the above, I start with some fundamental issues concerning the sources of theology and perspectives, and the nexus mysteriorum (Chapter 1).

Talking about God

In Christian tradition, it is customary to speak about God in terms of a ‘person’, even though Christian theology has always criticized the idea of an anthropomorphic (Greek: ‘made into the form of a human’) godhead. This critique was already found in the early Church Fathers such as Gregory of Nyssa (c. 335-c. 395) and later developed by the Dominican theologian Thomas Aquinas, who emphasized the analogical use of language about God, the via analogiae (Latin: ‘the way of the analogies’). Nevertheless, it appears to be very difficult to speak about God in other terms if one wants to maintain, at the same time, the idea of relationality (the idea of a relationship between God and created reality and of the possibility of people to know God), a trait the Christian tradition very much wants to keep intact for obvious reasons.

God has been given various qualifications that are generally accepted amongst theologians, like omnipotentia (Latin: ‘all-powerfulness’), omniscientia (‘all-knowing’) or omnibenevolentia (‘all-goodness’). The theologian Augustine of Hippo and Thomas Aquinas remain foundational for these classical divine attributes, which were later taken up in neo-Thomist frameworks by figures such as Jacques Maritain (1882–1973) and Reginald Garrigou-Lagrange (1877–1964). Christian theologians also attributed various divine transcendentalia (‘transcendentals’) to God: God is one (unum), true (verum), good (bonum), and beauty (pulchrum). These are concepts that again find their roots in Pseudo-Dionysius the Areopagite (late 5th-early 6th century), who greatly influenced medieval theologians like Bonaventure, who integrated the transcendentals with a Franciscan aesthetics and cosmology.

Again, in the Christian tradition, God is addressed predominantly in male terminology, like ‘Father’, ‘Son’, or simply ‘He’ (usually with a capital). Even though already in the Bible God is described with both male and female terms and analogies, the androcentric (‘male-dominant’) view of God has only recently been systematically criticized by feminist theologians. We cannot talk about God in any other way than by human expression (language) and thought, so theologians stress the inadequacy of these human faculties to say anything definite about God itself.

In this book, especially in this part on theology, I will refrain from capitalizing personal or possessive pronouns when referring to God. The capitalization of God’s pronouns is a sign of reverence, having its rightful place in worship, liturgy, and (private) devotion, but less so in academic theological discussions.

When I talk about God as Creator, I will use double-gendered language in singular (‘he/she, his/her, him/her’ depending on the context), since the Old Testament uses male and female imaginary for God.

When I talk about Jesus Christ or God the Savior, I will use male pronouns (‘he, his, him’), since the Bible talks about him in that way.

For the Holy Spirit or God the Whole-Maker, I will use female pronouns (‘she, her, her’), since the Spirit is associated in the Christian tradition with sophia (Greek: ‘wisdom’; Hebrew Chokmah), which is a female noun.

For addressing the Holy Trinity, I will use non-gendered language in plural form (‘they, their, them’).

Keepings one’s language in sync with the Christian tradition – that is to use exclusively male pronouns for God – is not wrong obviously, but I will use the alternative forms to sensitize theologians-to-be about the important and non-neutral role of language regarding God.

1. On fundamentals: notions and sources

Every academic discipline has certain fundamental issues, theology being no exception. While the separate discipline of Fundamental Theology discusses the philosophical premises of theology as an academic discipline, this chapter has a different aim: it provides key notions, and distinctions that are usually taken for granted in theology and theology courses. Especially for outsiders this information is crucial.

One to rule them all? The many sources of theology

‘Theology’ is a contraction of two Greek words, theos (‘god’) and logos (‘word’ or ‘discourse’). Theology means, literally, ‘the word/discourse of god’, in both possibilities of the genitive form ‘of’: the word spoken by god and the word spoken about god (or the discourse surrounding the notion of ‘god’). Since the Christian tradition upholds a firm monotheism (there is only one God), the word is written with a capital ‘G’. In fact, in Christianity, the word ‘God’ functions as a proper name. If (Christian) theology is the academic discipline dedicated to the scholarly search for knowledge of and about the (Christian) God, the question arises what the sources are for such an endeavor. These sources are called the loci theologici (Latin: ‘theological finding places’).

In Eastern Orthodox Churches, Anglicanism, and Catholicism, four sources of theology are generally recognized, even though the internal dynamics between the four can differ from time period to time period and from individual theologian to individual theologian. In many Protestant denominations, only one is recognized or at least heavily prioritized, at any rate officially: Scripture (sola scriptura, Latin ‘only through Scripture’). The four classical sources are:

Scripture, or ‘holy Scripture’ or ‘the Bible’: the authoritative canon (collection) of God’s revelation to the world.

Tradition: the collective ‘memory’ of the Church, handed down through the generations, including but not limited to the writings of saints, theologians, bishops, and popes, the decisions of Ecumenical Councils, liturgical practices, and creeds.

Human reason: the intellectual faculty given to human beings to discern truth, order, and meaning, including in connection to God.

Human experience: lived reality, both individually and communally, including but not limited to spiritual experiences, insight, and visions.

Besides these four major loci, there are other ones, for example philosophy, (non-Christian) culture, or other religions and spiritualities. If you want to argue anything theologically, you want to utilize as many sources as possible: the more the better. If a notion is only supported by one source, its legitimacy is easily questioned.

Perspectives, positions, and orientations

Theology can be done form different ‘angles’, so to speak: various perspectives, positions, and orientations come into play. For the purpose of this book, it is important that you have familiarized yourself with these notions, at least superficially.

First of all, we have the difference between an emic and an etic perspective (an epistemological category). A scholar using an emic perspective studies human phenomena, including religion, from within the community/tradition he or she is studying, using the language and categories provided by said community/tradition. When a scholar uses an etic perspective, he or she studies human phenomena from outside the community/tradition he or she is studying, using comparative or analytic language and categories provided by the academic field in question. Let us take for example the sacrament of baptism. A scholar using an emic perspective would describe the ritual in Christian terms like ‘annulment of sins’ and ‘becoming a part of the body of Christ’, while another scholar employing an etic perspective would describe the same ritual in terms of ‘initiation ritual’ or ‘water ritual’.

Secondly, we have the difference between the insider and outsider position (an existential category). The scholar having or adopting an insider position identifies with the (religious) tradition or group being studied, while the one having an outsider position, studies said tradition or group without such an adherence. To take the example of Christian baptism again, a scholar with an insider position self-identifying as a Christian, has very probably been baptized herself, while a colleague with an outsider perspective not.

The difference between the (emic and etic) perspective and the (insider and outsider) position is that the former is a choice, while the second usually is not. Any scholar can choose to study a phenomenon using the language and categories of the ones being studied, or not; while regarding position, scholars tend to find themselves in an insider or an outsider position per se, depending on their cultural or religious socialization. Of course, it is possible to access the language and categories of a group or tradition studied, but this consumes a considerable amount of time. The same applies to the insider position: one can attain such a position, in the form of accepting and adopting the tradition or group code in question, but again with much effort and – possibly – a life-long commitment.

Thirdly, we have the analytical orientation of inner or outer logic of a certain tradition or community. A scholar focusing on the inner logic of a tradition or community has to grasp the internal coherence of a cultic, religious, or cultural system as understood by its adherents. Conversely, the scholars focusing on the outer logic, interpret and report what they find through external frameworks (e.g. social or psychological). In our example of baptism, the inner logic is that through the water of the sacrament, the baptized is washed free from sin, while the outer logic has to do with identifying it as a ritual of initiation and a tool for community building. Both are true by the way.

Fourthly, we have the difference between theology and religion studies (disciplinary framework). Theologians aim to understand the religious tradition or group they themselves are a part of, while scholars of religion do the same, but without the self-identification. Of course, a scholar of religion (as a person) can self-identify as, for example, Roman Catholic, but this has no (or should not have) impact on the research he or she does as an academic, even if the research topic is located within the Christian tradition or world. Theologians regard their adherence to the faith they research as an advantage, even a necessity in many cases, while the scholars of religion adhere to methodological agnosticism (some will claim even atheism), offering other advantages.

Interestingly enough, religion studies and theology are not each other’s ‘archenemies’, even though some critics like to portray them as such. This is, however, unproductive, since theologians and religion scholars pose different questions and will, therefore. receive different answers, exactly because they have other perspectives, positions, and frameworks. A well-balanced theologian should also know a thing or two about religion studies, and ideally vice versa.

Maybe one of the most interesting differences between religion scholars and theologians is the appreciation for normativity. In religion studies, the focus is somewhat rigorously on descriptive language: describing phenomena without expressing any opinion. Theology, on the other hand, is not only descriptive, but also normative in nature: describing phenomena and judging their value in the light of the faith the theologian adheres to. Of course, any good theologian should also be very good at describing reality (and not only judging it), while scholars of religion are actually not (always) non-normative in their writings, especially when researching religion in connection with issues like power, gender, race, or ecology. In such cases, their work may include critical evaluations and ethical commitments, even if not grounded in a particular religious tradition.

Another difference, is that between the notions of ‘scholarly’ and ‘scientific’. In the English-speaking world, ‘scholarly’ is often used to denote the humanities, like sociology, psychology, philosophy, and theology, while ‘scientific’ is used for what is called the ‘natural sciences’, like physics and biology. In this usage, ‘scientific’ implies empirical methods, experimental verification, and quantifiable results, whereas ‘scholarly’ refers more broadly to rigorous, critical engagement with texts, concepts, and historical contexts. However, this distinction is not universal. Recently, we have seen a development of some of the humanities towards being ‘social sciences’.

In the German academic tradition, for instance, the term Wissenschaft encompasses both the humanities (Geisteswissenschaften, ‘sciences of the mind’) and the natural sciences (Naturwissenschaften, ‘sciences of nature’), implying that all systematic forms of knowledge, whether empirical or interpretative, are equally valid expressions of scientific inquiry. Similarly, the Dutch wetenschappen (‘sciences’) is comprised of geesteswetenschappen (‘sciences of the mind’, humanities) and exacte wetenschappen (‘exact sciences’, sciences of nature).

Readily, it becomes clear that certain perspectives, positions, orientations, and frameworks tend to coincide with one another: the theologian using an emic perspective, will probably have an insider position and be familiar with the inner logic of the group under research; and vice versa, the scholar of religion using an etic perspective, will have an outsider perspective, and use outer logic. However, cross-overs are certainly possible. An insider theologian can adopt an etic approach to their own and/or other tradition, while an outsider scholar of religion can aim for an emic understanding through methods like ethnography or textual immersion. And even more, interdisciplinary work increasingly blurs these lines, especially in contextual theology, interreligious dialogue, and lived religion studies. Thus, while theology and religious studies have different default orientations toward normativity, in practice the boundary is more porous than often assumed.

Another distinction is between synchrony and diachrony. Synchrony studies the meaning of a text, often the current text as it lies before us (in German often called Endtext, the ‘final text’). Diachrony studies the history of a text, how it originated and evolved. Synchrony thus focuses on a single moment in time, standardly the present, while diachrony focuses on a progression through history. This distinction is particularly relevant in theology within exegetical disciplines; but because theology works with a multitude of texts, this distinction is equally relevant in other theological disciplines.

Another distinction, even though maybe not as prevalent as the others, is that between exoteric and esoteric forms of knowledge. I start with the esoteric form, because adherents of esoteric knowledge will dub ‘conventional’ knowledge as exoteric, while conventional scholars will almost never self-identify as exoteric. Esoteric knowledge (Greek: ‘internal’) refers to inward, hidden, or secret dimensions of a teaching that require special initiation, insight, or intellectual/spiritual maturity to grasp. Exoteric (Greek: ‘external’) knowledge refers to outward, publicly accessible, and generally comprehensible aspects of a teaching, tradition, or religion. In modern lingo, esoterism is a container notion incorporating different kinds of ‘new’ spiritualities, including Theosophism (Helena Blavatsky), Anthroposophism (Rudolf Steiner), and various strands of Western occultism, neo-Gnosticism, neo-paganism, and New Age philosophies. At the university, the study of theology operates using exoteric knowledge (without explicating this as such), while esoteric knowledge is only present as a field of (historical) research.

Another distinction regards the role of the researcher. Traditionally, especially in the positivist paradigm, a researcher is expected to describe phenomena from an objective, detached standpoint, maintaining critical distance in order to produce objective knowledge. Involvement or immersion is seen as a potential source of bias. However, this model has been increasingly challenged by other forms of research, especially participatory research and action research, predominantly in the fields of anthropology, religious studies, sociology, and theology.

Participatory research entails a methodological stance in which the researcher actively collaborates with the community or group being studied, often with the aim of co-producing knowledge that is both academically valid and socially relevant. Action research goes a step further by explicitly aiming to bring about change through cycles of reflection, planning, action, and evaluation. In both approaches, the boundary between the researcher and the researched is deliberately blurred.

The ‘nexus mysteriorum’

Within theology, an important notion is the nexus mysteriorum (Latin: ‘the interlinking of the mysteries’), the idea that the core mysteries of the Christian faith (such as the Trinity, the Incarnation, et cetera) are not isolated doctrines but are principally interconnected in such a way that understanding one topic always implies understanding the other ones. A metaphor could be that of a tapestry: when pulling one string the whole tapestry is affected, technically and aesthetically.

So, any attempt to diversify the various (sub)disciplines within theology is perilous and dependent on specific cultural-historical circumstances (which has not stopped theologians from trying). For the purpose of this book, the attempt I make to construct an interconnected overview of the disciplines is not aimed at delivering a final verdict but to assist the non-initiated in navigating this academic maze and its often cryptically sounding nomenclature. The sections below correspond with various chapters of this book’s first and second part (given between brackets).

Fundamental theology explores the foundations of theology, including revelation, faith, and the relationship between reason and faith (chapter 1).

Systematic theology organizes and articulates the doctrines of the Christian faith in a coherent and comprehensive way.

Creation theology reflects on God-as-Creator and the theological meaning of the created world, including humanity’s place in it (chapter 3).

Christology, closely connected to Soteriology, examines the person and work of God-as-Savior, Jesus Christ, including his divinity, humanity, and salvific mission (chapter 4).

Soteriology, closely connected to Christology, investigates the doctrine of salvation, including grace, redemption, justification, and the role of Christ’s passion and resurrection (chapter 4).

Pneumatology focuses on God as Whole-Maker, the Holy Spirit, her identity, presence, and activity in the Church and the world (part 2, chapter 5).

Trinitarian theology explores the mystery of the Triune God: Father, Son, and Holy Spirit, and their relational unity (part 2, chapter 2).

Theodicy studies the question of the existence of God vis-à-vis the existence of evil, pain, and suffering in the world (chapter 6).

Theological anthropology studies the human being in light of God’s revelation, including human nature, sin, freedom, and vocation (chapter 7).

Sacramental theology analyses the nature, purpose, and efficacy of the sacraments as means of grace and signs of faith (part I, chapter 6; part 2, chapter 8).

Ecclesiology reflects on the nature, mission, structure, and sacramental life of the Church (part I, chapter 7; part II, chapter 9)

Theology of the religions examines the theological meaning of religious plurality and the relationship between Christianity and other faiths (chapter 10).

Theology of culture investigates the interaction between faith and cultural expressions, practices, and worldviews (chapter 11).

Eschatology concerns the ‘last things’: death, judgment, heaven, hell, and the ultimate fulfilment of creation (chapter 12).

Practical theology applies theological insight to the lived practice of faith in contemporary contexts.

Pastoral theology addresses the spiritual care of individuals and communities.

Diaconia (Greek: ‘service’) addresses the spiritual and material care for the poor and marginalized.

Church development encompasses the theological and pastoral process of strengthening the local faith community.

Homiletics (Greek: homiletikos, ‘assembled crowd’) is the art and theology of preaching and sermon writing, focusing on the communication of the gospel in worship and mission.

Pastoral Care, or Poimenics (Greek: poimen, ‘shepherd’) focuses on counseling and spiritual direction for individuals and communities.

Liturgical studies explores the history, theology, and practice of Christian worship and its ritual forms (part I, chapter 5).

Christian education focuses on faith formation, catechesis, and religious education in general.

Missiology studies the theology, history, and practice of the Church’s mission in the world, including evangelization, inculturation, dialogue, and service, in light of the Trinitarian sending of the Church (chapter 12).

Moral theology reflects on human action in the light of faith and revelation, exploring ethical principles, virtue, conscience, and the moral implications of Christian discipleship (part I, chapter 10).

Church history traces the historical development of Christianity, its institutions, doctrines, and cultural impact (part I, chapter 4).

Canon Law studies the legal framework of the Church, including its governance, rights, and obligations (part I, chapter 7).

Exegesis engages in the critical interpretation of biblical texts, from both a synchronic and diachronic perspective, analyzing language, context, meaning, and reception (part I, chapter 2).

Besides these traditional theological disciplines, modern theologians also make use of other disciplines, like philosophy, social sciences, religion studies, et cetera.

The winner takes it all: orthodoxy, heterodoxy, and heresy

Within theology, there is a tension between the notions of ‘orthodoxy’ (Greek: ‘correct opinion’), ‘heterodoxy’ (Greek: ‘other opinion’), and ‘heresy’ (Greek: ‘choice’). The word doxa originally means ‘praise/worship’, making ‘orthodoxy’ into ‘to worship correctly’, yet another example of the adage lex orandi, lex credendi (the idea that the ‘law of praying’ comes before the ‘law of believing’).

Orthodoxy refers to theological doctrines that are officially accepted as true and authoritative by a religious community, most often by its ecclesial hierarchy or through conciliar decisions. Heterodoxy refers to theological positions that deviate from accepted doctrine but do not necessarily place one outside the community of faith. Heterodox views may represent speculative theology, minority positions, or theological innovations that remain under the broad tent of ecclesial discourse. Heresy, on the other side, has come to denote a persistent, willful rejection of an essential doctrine of the faith, as judged by said ecclesial authorities.

In popular parlance, the terms ‘heterodoxy’ and ‘heresy’ are frequently used as synonyms. Besides being historical categories, orthodoxy, heterodoxy, and heresy are also normative categories within the framework of Christianity. The last two are used to disqualify theological adversaries, while the first is claimed as kind of seal of approval. This is, however, usually rather unfruitful.

In theology, the primary concern is not to claim ‘the Truth’ (in the sense of a system of doctrines), but to seek the One who is Truth itself (in the sense of God). The search for truth lies at the heart of theology, but so does humility in making exclusive claims to that truth. This insight is primarily guarded in the so-called ‘apophatic’ theology (Greek: apophasis, ‘denial’), or ‘negative theology, a theological approach that emphasizes what cannot be said about God rather than what can be said. The most truthful way to speak about God is, then, by negation, that is, by stating what God is not.

Moreover, what is considered orthodoxy can only be determined retrospectively; it cannot be defined in the present, let alone for the future, even though ecclesial bodies, like synods, councils, popes, and dicasteries try to do so. Only history can ultimately establish what is orthodoxy, in hindsight: one can determine orthodoxy/heterodoxy usually only decades or even centuries after the actual theological debate took place. As the popular expression goes, the winner dictates history. In theological terms, this means that the theological position that has accumulated the most ecclesial and political influence has ‘won’ the debate and can therefore dictate what is deemed orthodox (itself) and what is deemed heterodox (the group that lost the debate).

Therefore, ‘the opinion of the Catholic Church’ (or any Church or denomination for that matter) is usually a construct created by those in institutional power to force through their views, opinions, and interpretations as if they were Christ’s, arguably disqualifying all other ones as either heterodoxy or heresy.

Favorite frenemies: faith and science

Faith and science are frequently placed in extreme opposition to one another, especially in popular speech. In this type of thought, usually from a secular point of view, religion stands for intuition, experience, emotions, feelings, and sometimes also for indoctrination and an absolute worldview, while science represents reason, evidence, logic, objectivity, and freedom. This dichotomy suggests an inherent incompatibility between the two: religion is seen as subjective and premodern, whereas science is viewed as universal and progressive.

However, there are various positions one can take within this discussion, some of them keeping the two far apart, while others strive for a more inclusive approach. For the purpose of this paragraph, I make use of Ian Barbour’s influential four-tier division, published in 1997 as Religion and Science by HarperSanFrancisco: conflict, independence, dialogue, and integration.

To simplify matters, I will make use of a metaphor involving two young children, both locked up in a sealed room (it is a metaphor, so no actual children were being harmed) with a mountain of toys in the middle of the room with which they can freely play. One child is called Stephen and embodies science, the other is called Joseph and stands for religion. The heap of toys represents reality.

One possible way of looking at the relation between faith and science is through the model of conflict. Science and religion are principally in conflict: the truth of the one means the lie of the other. This model became popular in the USA in the 19th century. This type of thinking leads to two extremes on both sides. On the side of science, this conflict mode leads to scientific materialism, arguing that the empirical scientific method is the only reliable path to knowledge and that (in a reductionist way) matter is the fundamental reality of the universe. This idea reduces all phenomena to their material form (also known as nothing-but-ism). Trees are nothing but oxygen producers, human love is just genes that want to multiply, and our identity is nothing but electrical impulses in our brains. On the side of religion, this stance leads to biblical literalism, where there is no discrepancy between the text of the Bible and the reality outside that text. This, in its own turn, lead to ideas like ‘Young Earth Creationism’, arguing that the world is between 10,000 and 6,000 years old based on the book of Genesis. Both positions are not really academic, since they both considerably simplify reality.

In our metaphor, both Stephen (science) and Joseph (religion) are standing in the center of the room, holding tightly on to one and the same toy, screaming at one another, while trying to take the toy for themselves alone, because both are convinced that only they can handle the toy properly and that the other has to, therefore, back off.

The second possible relationship between science and religion is that of independence, or ‘non-overlapping magisteria’ (NOMA), coined by Stephan Jay Gould in his 2002 book Rock of Ages, originally published by Ballatine Books. It suggests that both religion and science have a genuine claim to the truth about reality, but in different ways. Science seeks to explain objective, publicly available, repeatable phenomena, while religion asks about the existence of order and beauty in the world and the experiences of our inner lives. Science asks objective ‘how’ questions, while religion asks personal ‘why’ questions about the meaning, purpose, and our ultimate origin and destiny.

The basis of authority in science is logical coherence and experimental adequacy, while the final authority in religion lies in God and revelation, understood through persons to whom enlightenment and insight have been given, and validated in our own experience. Science makes quantitative predictions that can be tested experimentally, while religion must use symbolic and analogical language because God is transcendent. Scientific language is used primarily

for prediction and control. Religious language is to recommend a way of life, to elicit a set of attitudes, and to encourage allegiance to particular moral principles.

In our metaphor, we have Stephen and Joseph in opposite corners of the room, both playing with their own set of chosen toys. They no longer fight over who gets what toy, but there is no interaction between them: they are not curious about one another, nor interested in each other’s toys.

The third option is dialogue between faith and science. They can ask one another difficult questions about implicit prepositions, limitations, and fallacies. This dialogue does not imply simple agreement but mutual engagement. Scientific inquiry rests on certain foundational assumptions (the universe is orderly and intelligible to the human mind for example), but it cannot empirically prove these assumptions, since they are metaphysical in nature. Secondly, the traditional Enlightenment-era dichotomy – science as purely objective, religion as purely subjective – has come under scrutiny, especially in the philosophy of science: science is shaped by paradigms and models, traditions, values, and even personal commitments. Likewise, theology is not the mere projection of feelings, but often involves conceptual work and communal interpretation. And thirdly, science and religion can warn one another about either fringe science (or pseudo-science) and para-spirituality, when religion and science are merged in uncritical ways (like quantum mysticism or the Gaia hypothesis).

In our metaphor, Stephen and Joseph are standing facing towards one another in the middle of the room. They are still holding on to their own set of toys, but they curiously inquire about the ones used by the other, eager to understand their workings and (im)possibilities.

The fourth option in that of integration (or synthesis) between science and religion, on the basis that both can converge regarding certain common metaphysical or ontological commitments, for example, the rationality, order, and intelligibility of the universe. Secondly, theological claims (on creation or human nature) and scientific claims (about cosmology or evolution) can be, according to this model, reconciled into a single unified framework. Historically, we see examples in notions like natural theology (using empirical observations to support arguments for God’s existence) and process theology (God as a self-unfolding universal process). In contemporary theological circles, integration often emerges around shared ethical concerns, such as climate change, technological responsibility, and bioethics. Here, theology and science collaborate not just to understand the world, but to shape human action within it.

In our metaphor, Stephen and Joseph are now playing together with the same toys.

2. On the One and Three God: a conundrum (Trinitarian theology)

Already from the very beginning, in the Early Church, believers worshipped God in the Christian liturgy as Father, and Son, and (Holy) Spirit, and believers were also baptized in the name of the same Father, and Son, and Holy Spirit. These liturgical practices preceded the official formulations of later doctrines. This is an example of the old idea (proposed by Prosper of Aquitaine, 390-455) of lex orandi, lex credendi, or ‘the law of praying’ takes priority over ‘the law of believing’.

This naturally raises the question: if Christianity is strictly and fundamentally monotheistic (affirming the belief in one God), how can one speak of three divine persons, Father, Son, and Holy Spirit? Christians do not subscribe to tritheism (the belief in three separate gods), though they have often been accused of it (and still are). At the same time, modalism, the idea that Father, Son, and Spirit are merely three modes or manifestations of one and the same divine person, has also proven inadequate, as it fails to account for the genuine relational distinctions evident in the biblical witness. Similarly, partialism, the notion that each of the three is only a part of God and that together they make up the whole, is rejected as heterodox, since each person of the Trinity is fully and wholly God.

The ’immanent’ Trinity

The discussion on the inner relationships between the three persons of the one godhead is technically known as the discussion about the ‘immanent’ Trinity. The now ‘orthodox’ doctrine affirms one God who exists as three distinct persons (Latin: persona; Greek: hypostasis) – Father, and Son, and Holy Spirit – who share one divine substance (substantia, or ousia). The term ‘consubstantial’ (Latin: consubstantial, or Greek: homoousios) expresses that the three persons are fully equal in divinity and being. The Protestant theologian Karl Barth and the Roman Catholic theologian Karl Rahner both emphasized ‘relationality’. Similarly, Orthodox theologian John Zizioulas (1931-2023) stressed the relational identity of God by understanding the divine person not as an individual, but as constituted by relation, especially within a Trinitarian framework in which the Father is the relational origin of the Son and the Spirit. Jürgen Moltmann also developed a ‘social’ doctrine of the Trinity, in which the divine persons are understood as mutually indwelling in love, providing a theological foundation for human community and solidarity. Leonardo Boff connected relationality with social and ecological concerns, interpreting the Trinity as a model for just and communal living.

The ’economic’ Trinity

Besides the idea of the ‘immanent Trinity’, Christian tradition also has the notion of the ‘economic’ Trinity. According to Karl Rahner’s famous adage, ‘the economic Trinity is the immanent Trinity, and the immanent Trinity is the economic Trinity’. The ‘immanent Trinity’ is about how God is in Himself from all eternity. The ‘economic Trinity’ refers to how God is for us; how He reveals Himself in history. God reveals him/herself in what is called the economy of salvation (Greek: oikonomia, ‘the way things are arranged’) as Creator, Savior, Whole-Maker. All three designations for God emerge from and appear within the New Testament, both in the four Gospels and in the apostolic letters. Jesus speaks of his/our ‘Father in heaven’ and refers to himself as God’s Son, although he more often accepts that designation from others than claiming it directly himself; furthermore, the title is not exclusive, for everyone who does the will of God is considered a son or daughter of God. The Gospels and apostolic writings also refer to the ‘Spirit of God’ who rested upon Jesus and whom Jesus promised to give to his disciples after his death, resurrection, and ascension.

Processions and missions

Trinitarian theologians frequently and historically use two concepts to think about the mutual relationships between the three persons within the Trinity, ‘processions’ and ‘missions’. Processions refer to the eternal, internal relations within the immanent Trinity, that is, how the persons relate to each other in themselves, independent of temporality. The key points are that, within the one godhead: (1) the Father begets (or generates) the Son; this begetting is eternal and not temporal, meaning that the Son is eternally begotten or generated from the Father. (2) The Holy Spirit proceeds from the Father (in Eastern theology) or from the Father and the Son (in Western theology, due to the Filioque-clause, see below).

Later theologians coined the term ‘spiration’ (or ‘breathing out’) to distinguish the procession of the Spirit from the begetting of the Son. Of course, terms like ‘generation’ (= ‘begetting’) and ‘spiration’ should not be taken in a physical sense. Church Fathers like Augustine explained ‘generation’ as the intellectual procession of an ‘inner word’ or ‘concept’ in which the Father perfectly utters his own self-understanding. And he explained the procession of the Spirit as the mutual love between Father and Son, in which God perfectly loves Himself/Herself. All this language attempts to maintain the unity of God while acknowledging real distinctions among the three divine persons.

Missions, on the other hand, refer to the external activity of the Son and the Spirit in the history of salvation, that is, how God acts in creation, redemption, and sanctification. This is called the ‘economic Trinity’; it indicates the distinct roles each divine person plays in the world: (1) The Father is often described as the origin or source, the one who sends the Son and the Spirit. (2) The Son is the one who is sent into the world for the work of salvation (incarnation, life, death, resurrection). (3) And the Holy Spirit is the one who is sent by the Father and the Son to sanctify, guide, and empower the Church. This understanding preserves the unity of God’s work while emphasizing the distinct roles of each divine person in salvation history.

Filioque controversy

Over time, the Western and Eastern Churches developed different theological emphases in their understanding of the internal relations within the Trinity. In both traditions, it is affirmed that the Father eternally begets the Son, but differences arise in the understanding of the Holy Spirit’s procession. In the Eastern Churches, the Spirit is said to proceed from the Father alone, in line with John 15:26 and the teaching of the Cappadocian Fathers. In contrast, Western theology, especially since Augustine, has taught that the Spirit proceeds from the Father and the Son.

This divergence is known as the Filioque controversy, named after the Latin phrase filioque (‘and [through] the Son’), which was added to the Nicene-Constantinopolitan Creed in the Western Church. The relevant clause reads, in Latin: Et in Spiritum Sanctum, Dominum et vivificantem: qui ex Patre Filioque procedit (‘and [I believe] in the Holy Spirit, the Lord and giver of life, who proceeds from the Father and the Son’).

Although the controversy surrounding the doctrine of the divine processions historically contributed to the East-West Schism, the theological divide itself is no longer regarded as church-separating. The mutual excommunications were formally lifted in 1965 and declared to be ‘removed from the memory of the Churches’. Even more, subsequent bilateral dialogues, already in 1969, recognized that neither the Filioque nor questions of primacy constitute grounds for separation today.

Within this ecumenical context, both traditions affirm the external, or economic, missions of the divine persons: the Father sends the Son into the world for redemption, and the Spirit is sent for the sanctification of creation. It is therefore noteworthy that popes, including Francis and Leo XIV, have on various occasions recited the Creed without the Filioque, underscoring this shared theological horizon.

***

The first sections of Part II of this book are arranged following the economic Trinity: God as Creator (chapter 3), God as Savior (chapter 4), and God as Whole-Maker (chapter 5). But remember, all three persons of the Trinity (Father, Son and Spirit) participate in all three works (Creation, Salvation, Whole-Making), even though each work is associated with one divine person specifically.

3. On the Triune God, part 1: God the Creator (creation theology)

The idea of God as Creator of ‘heaven and earth’, that is, of everything that exists, is already present in the first two chapters of the Book of Genesis, at the beginning of the Old Testament. God creates by the act of speaking in a timespan of six days, leaving the seventh day to rest. The majority of Christian theologians regard the number of six days symbolically, following Origen of Alexandria and later Augustine of Hippo, even though some more literalist interpreters, found in strands of American fundamentalism, argue otherwise.

Within Christian tradition, God creates freely and ex nihilo (Latin: ‘out of nothing’), as defended by Theophilus of Antioch (2nd century) and systematized by Thomas Aquinas, vis-à-vis the idea of an artist or an architect who creates by rearranging pre-existing objects and matter, or the idea of a fountain flowing over naturally and not by free choice. In short, God is free to create and creation does not presuppose anything.

The idea of God as Creator has some important consequences for Christian theology. First of all, Creator and creation are very closely related but are not identical, vis-à-vis the idea of pantheism (Latin: ‘God is all’), which was notably rejected by Gregory of Nyssa and Maximus the Confessor, and later nuanced in panentheistic (Latin: ‘all is in God’) frameworks such as that of Teilhard de Chardin (1881–1955). Secondly, God has power and authority over creation, precisely because God created it from nothing, a conviction strongly defended in the classical theism of Anselm of Canterbury and Thomas Aquinas.

Thirdly, the creation is initially good and beautiful - Genesis repeats the phrase ‘God saw it was (very) good’ – even though humanity desecrated it later because of its many vices (see further in Chapter 7). Fourthly, God created humanity in their own image (called the imago Dei, ‘image of God’), through which God and humanity have something in common, even though that something is the object of continuous theological debate, ranging from the focus on rationality in Irenaeus of Lyon and other early theologians via the functional model of humanity having to take care of creation on behalf of God as found in John Chrysostom, to the relational anthropology of Barth and Moltmann.

Many analogies have been suggested to explain God’s creative effort, among which some are most prevalent. The first is emanation, the idea that creation flows from the divinity itself; this model can be found in the work of the non-Christian philosopher Plotinus (c. 204/5–270) and influenced early Christian thought. However, later this idea was largely rejected by mainstream theology for excluding a free decision on the part of God, a feature central to the Christian doctrines of divine will and freedom, especially in Augustine and Bonaventure. Another common analogy is that of creation-as-construction or as a form of artistic expression; both have the advantage of suggesting a caring and loving relationship between creator and created, but the disadvantage of also suggesting that God worked with pre-existing materials, something the ex nihilo doctrine forbids. Still, Gregory Nazianzen and Hilary of Poitiers (c. 310–367) used artistic metaphors with caution to underscore divine intentionality and order.

‘Creatio continua’

In Christian tradition, God is usually thought to have a continuous relationship with, engagement with, and commitment to the work of his/her hands; this is the idea of creatio continua (‘continuous creation’). This continuous engagement can be understood differently depending on one’s theological preferences and ideas. God can be seen as a monarch, who controls and rules everything with sovereign power, an idea prominent in Reformation-era theologians like John Calvin. Yet another option is to see God as the prima causa (Latin: ‘first cause’), a concept rooted in Aristotle and integrated into Christian theology by Aquinas.

Another possibility is that of God as a process manager (who is also himself/herself involved in the changes that occur in these processes), characteristic of process theology, pioneered by Alfred North Whitehead (1861-1947) and developed theologically by Charles Hartshorne (1897-2000) and John B. Cobb Jr. (1925-2024). Finally, God can be seen as what is experienced by individual believers. This is reflected in the works of theologians as Paul Tillich and Bultmann, who emphasized God not primarily as metaphysical agent but as existential depth and meaning.

4. On the Triune God, part 2: God the Savior (Christology and soteriology)

In the context of theological discourse about Jesus Christ, a (dynamic) distinction is often made between Christology (the person of Christ) and soteriology (the work of Christ). Both are treated here together. Several aspects concerning the figure, person, and function of Jesus Christ are more or less uncontested within the Christian tradition:

Jesus Christ is the historical starting point of Christianity and the Christian faith.

Jesus Christ reveals himself as God (the Son) and is the revelation of God (the Father).

Jesus Christ is the bringer of divine salvation for all people.

Jesus Christ is the perfect imago Dei, the ideal/perfect human being.

The New Testament uses several (biblical) titles for Jesus that require some explanation.

Messiah (Greek: christos; Aramaic: mashiach, ‘anointed one’). In the Old Testament, priests, prophets, and kings are anointed by or on behalf of God (i.e., divinely sanctioned), but the word ‘messiah’ itself is hardy used in the Old Testament. In later Jewish perspective, the Messiah was the expected Davidic king who would restore Israel’s independence from its (Mesopotamian, Greek, and later Roman) occupiers. We do not know how the historical Jesus understood his role, but at least some of his followers were very contemporary-politically motivated (including Judas Iscariot, who would betray Jesus eventually).

Son of God (Hebrew: ben Elohim). In the Old Testament, the term ‘son of God’ is synonymous with ‘one who walks the path of God.’ It was used for the entire people of Israel and for individual believers (especially the Davidic kings).

Son of Man (Hebrew: ben-adam; Aramaic: bar adam or bar nasha, ‘son of humans’). In the Old Testament, this title is applied to the prophet Ezekiel, to a future eschatological figure (in the book of Daniel), and as a designation of the contingency (finitude and brokenness) of human life.

Lord (Greek: kyrios; Aramaic: mar). In the Old Testament, the word Adonay (‘Lord’) is used as a spoken substitute for the revealed divine name YHWH, the sacred name revealed to Moses (in the biblical book of Exodus), traditionally considered too holy to pronounce. To call Jesus ‘Lord’ evokes the association that Jesus is the revelation of the divine name and thus of God Himself.

God. In the Old Testament, only the God of Israel is identified and addressed as such. This also applies to the New Testament.

Incarnation. The Gospel of John reveals Jesus as the incarnated Word, that is, that the eternal Word of God has become ‘flesh’ (Latin: in carno, ‘into the flesh’) in Jesus Christ.

Christological issues

Christology has experienced a rather turbulent history, with several key turning points. In general, Jesus Christ is understood as the mediator between the Creator and fallen humanity; therefore, Christ is ‘from both sides,’ God and human at the same time. This duality is classically formulated in the doctrine of the ‘hypostatic union’, as articulated at the Council of Chalcedon (451), influenced by theologians such as Cyril of Alexandria and Pope Leo the Great.

In many cases, Christological doctrines were established because of theological discussions concerning the figure and identity of Jesus (God, human, or both). A number of historical groups tried to define the divine-human relationship within Jesus Christ. Adoptionists, such as Theodotus of Byzantium (late 2nd century), claimed that Jesus became the Son of God only at his baptism in the Jordan, when the Spirit descends upon him, thus ‘adopting’ him as God’s son (a position later rejected as heterodox). Docetism, already challenged by Ignatius of Antioch (c. 35-108), considered Jesus as purely divine, only appearing (Greek: dokein) to be human.

The followers of Arius (c. 256-336), known as Arians, held that Jesus was a created being, higher than humans but not fully divine, leading to the formulation of the Nicene Creed (325 CE), shaped under the influence of Athanasius of Alexandria, which affirmed the full divinity of Christ as ‘consubstantial’ (Greek: homoousios, ‘of one and the same substance,’ or essence) with the Father. Generally speaking, the theological position that Jesus has two natures has prevailed: one human nature and one divine nature, which – according to the classic, ‘negative’ definition of the Council of Chalcedon – are unmixed, undivided, unchanged, and unseparated.

‘Leben Jesu Forschung’

During and after the Enlightenment, a search for the historical Jesus took off, especially at the end of the 19th century. The so-called Leben-Jesu-Forschung (German: ‘research into the life of Jesus’) sought to reconstruct the historical Jesus of Nazareth ‘behind’ the poetic theology of the New Testament Gospels, which supposedly turned the human Jesus into the divine Christ. This movement included thinkers such as David Friedrich Strauss (1808–1874) and Ernest Renan (1823–1892), who viewed the Gospels largely as mythological or legendary expansions. The so-called ‘first quest’ for the historical Jesus was later critiqued by Albert Schweitzer (1875–1965), who argued that these reconstructions reflected modern ideals more than ancient realities and presuppositions.

In the 20th century, Rudolf Bultmann added a highly influential dimension with his program of Entmythologisierung (German: ‘demythologisation’), insisting that the mythological worldview of the New Testament must be reinterpreted existentially in order to recover the ‘kerygmatic’ (Greek: ‘proclamation’) core of the Christian message. More recently, The Jesus Seminar was a group of scholars (active mainly in the 1980s and 1990s) who used historical-critical methods and voting procedures to distinguish what they believed were the authentic sayings and deeds of Jesus (the so-called ipsissima verba, or ‘the very words themselves’) from later additions. The problem is, however, that the New Testament books are the oldest sources we have on the historical Jesus; of course, there is a Jesus ‘behind’ the Gospels, but going ‘beyond’ them is practically impossible.

Redemption

In the Christian tradition, the notion of salvation or redemption is intrinsically linked to the life, death, and resurrection of Jesus Christ (soteriology). This salvation is realized in individual believers gathered in the Church, who strive to follow Christ in their own lives, while at the same time, God is actively transforming these individuals into the likeness of Christ through the work of the Spirit. This dynamic understanding of sanctification is notably emphasized in the theology of Gregory of Nyssa and later John Wesley (1703–1791). (That from which human beings need to be saved is – put briefly – their own sinfulness; see below under Chapter 7.) The salvation or redemption accomplished by Christ on behalf of humanity is centered on his death (on the cross) and resurrection. Within this framework, some major themes can be distinguished:

Theme 1: the cross as sacrifice. Christ’s death on the cross as a continuation or fulfilment of the Jewish sacrificial cult. This interpretation, grounded in the Epistle to the Hebrews, was developed by Athanasius of Alexandria and further elaborated by Origen. Theme 2: the cross and resurrection as victory (Christus Victor). Christ’s crucifixion and resurrection as a victory over death, sin, and the powers of evil. This model has roots in the early Church Fathers, such as Irenaeus of Lyon and Gregory Nazianzen. Theme 3: the cross as satisfaction. Christ’s death as a ‘payment’ to God for humanity’s many sins. This theory was most clearly formulated by Anselm of Canterbury arguing that human sin offended God’s honor and that Christ, as both God and human, alone could render adequate satisfaction (so-called ‘Satisfaction Theology’).

Theme 4: the cross and resurrection as moral example or expression of love. Christ’s death is the ultimate expression of loyalty to God and love for humankind, inspiring believers to live accordingly. This ‘moral influence theory’ was notably developed by Peter Abelard and was later retrieved by Friedrich Schleiermacher and various liberal Protestant theologians. Theme 5: salvation as healing from the disease of sin, with Christ as the doctor (medicus) and the sacraments as medication for the sick/sinners. Both Augustine and Thomas Aquinas developed this analogy. Theme 6: salvation as the cleansing of the stain and ugliness of sin. The death of Jesus on the cross is interpreted as the washing away of humanity’s sins. Anselm of Canterbury and Martin Luther are defenders of this idea.

Salvation

This salvation and redemption accomplish several important things for believers. First, God became human (the idea of the incarnation) so that the human being might become divine, a process known as theosis or deification. This concept is central in Eastern Christian theology, particularly in the thought of Athanasius of Alexandria, who famously stated, ‘God became man so that man might become God’, and was further developed by Gregory Palamas (c. 1296–1359). Secondly, humanity is justified before God, with its sins being taken away.

Thirdly, humanity returns to its original, intended way of being, as it was created by God. This restorative aspect of salvation was emphasized by Irenaeus of Lyon, who described Christ as the ‘recapitulation’ of humanity, restoring the human race to its original purpose. Additionally, Christ liberates human beings from sinful structures as well. This liberationist perspective, which views sin not only as personal guilt but as embedded in unjust social, political, and economic systems, was articulated by theologians such as Gustavo Gutiérrez and Leonardo Boff, key figures in liberation theology.

The question of who exactly is saved, or will be saved, is difficult to answer and has led to several theological positions. One is universalism, the view that all will ultimately be saved, which was cautiously proposed by Origen of Alexandria and more openly embraced by modern theologians such as Hans Urs von Balthasar (1905-1988). Another position holds that salvation is only for those who believe, a more exclusivist stance found in classical Christian orthodoxy, including the writings of Augustine of Hippo and the Protestant Reformers. Finally, the doctrine of predestination, which teaches that only those elected by God will be saved, was strongly emphasized by Calvin and other theologians of the Protestant Reformation, taking their cue from Augustine.

5. On the Triune God, part 3: God the Whole-Maker (pneumatology)

God the Whole-Maker, or the Holy Spirit, has traditionally received the least attention among the three persons of the Trinity, at least in the Western Churches. Even more, in the 4th and 5th centuries, a group called the Pneumatomachi (Greek: ‘combaters against the Spirit’) denied the divinity of the Spirit. The Council of Constantinople, however, rejected this position, upholding the Spirit’s divinity.

However, with the emergence of the Charismatic Renewal, this imbalance has been substantially redressed in contemporary theology and spirituality. The Second Vatican Council also made significant strides in addressing the longstanding Geistvergessenheit (German: ‘the neglect of the Holy Spirit’) in Roman Catholic theology. Especially in Lumen gentium and Gaudium et spes, the Council emphasized the active role of the Holy Spirit in the life of the Church, in the sanctification of the faithful, and in the discernment of the signs of the times. The Spirit is no longer presented merely as an auxiliary force but as a central agent in the ongoing revelation, mission, and renewal of the Church.

Various models have been developed to conceptualize the Spirit and the Spirit’s role as the one who brings divine work to completion. In the Old Testament, the Spirit is represented in several metaphorical ways. First, the Spirit is likened to the wind, as God’s breath is depicted as a dynamic and life-giving force (Genesis 1:2). Second, the Spirit is portrayed as God’s breath in a more literal sense, as in the creation account where God breathes the breath of life into the human being (Genesis 2:7). Third, the Spirit is understood as charisma, the divine inspiration granted to individuals, often associated with a specific calling or mission (Numbers 11:25-29). A fourth model is thinking of the Spirit in terms of Sophia, or ‘Wisdom’. In the New Testament, the Spirit is primarily described as the Helper or Advocate (Parakletos), promised by Christ to his followers as a continuing divine presence (John 14:16; 15:26; 16:7).

Traditionally, three principal functions are attributed to the Spirit in Christian theology. The Spirit acts as the Revealer, mediating the self-communication of God to humanity. This revelatory role was notably developed by Rahner, who emphasized the Spirit’s role in the ongoing divine self-disclosure in human history. The Spirit is also the Sanctifier, transforming human beings into the image of God through an ongoing process of sanctification, a theme central in the theology of Augustine, who wrote extensively on the Spirit’s sanctifying grace. Finally, the Spirit functions as the Inspirer, awakening in individuals the capacity to comprehend, praise, and glorify God. This aspect of the Spirit’s work was central to the pneumatology of Moltmann, who highlighted the Spirit’s empowering presence for human hope and worship.

The Charismatic Renewal

The Charismatic Renewal originated in the 18th century within Evangelical and Pentecostal Protestantism, and represents a significant movement emphasizing the experiential presence and gifts of the Holy Spirit, such as speaking in tongues, prophecy, healing, and other charismatic manifestations. This movement sought to renew established Churches by fostering a more immediate and dynamic encounter with the Spirit, often marked by vibrant worship and personal conversion experiences.

Beginning in the late 1960s, the Charismatic Renewal crossed denominational boundaries and gained notable traction within Roman Catholicism, where it came to be known as the Catholic Charismatic Renewal. This development was marked by a renewed emphasis on the Spirit’s role in personal sanctification, communal renewal, and evangelization, resonating with the Catholic Church’s broader theological tradition while also introducing more spontaneous forms of worship and prayer.

Gifts and fruits

In Roman Catholic theology, a distinction is made between the gifts and the fruits of the Holy Spirit, both of which express the Spirit’s work in the life of the believer, yet in different ways.

The gifts of the Holy Spirit, as listed in Isaiah 11:2-3, are understood as permanent dispositions infused by God that make the soul docile to divine guidance. These seven gifts – wisdom, understanding, counsel, fortitude, knowledge, piety, and fear of the Lord – are not acquired through human effort but are graciously bestowed by the Spirit. They elevate and perfect the theological and moral virtues, enabling believers to act under the impulse of the Spirit. Rooted in sanctifying grace, these gifts are traditionally associated with the sacraments of baptism and confirmation, where they respectively begin and are deepened. Their purpose is to assist the faithful in their journey toward holiness, allowing them to discern and respond to God’s will more fully.

Additionally, the fruits of the Holy Spirit, as outlined in Galatians 5:22-23, are the visible expressions or manifestations of a life lived in harmony with the Spirit. They represent the moral and spiritual transformation of the person who cooperates with divine grace. In the tradition, twelve fruits are named: charity (love), joy, peace, patience, kindness, goodness, long-suffering, mildness, faithfulness, modesty, continence, and chastity. These fruits are not merely virtues or good habits, but rather the tangible outcomes of sanctification, signs that the Spirit is actively shaping the believer into the image of Christ.

6. On the problem of God and evil (theodicy)

One of the more haunting, if not the most haunting, problems in Christian theology, or in every monotheistic system, is that of the existence of evil, pain, and suffering. If an entity is entitled to be called ‘God’, at least in a monotheistic, especially Christian context, this entity must have at least two characteristics: omnipotentia (being all-powerful) and omnibenevolentia (being all-benevolent). But how can one negotiate the existence of an all-powerful and all-good God vis-à-vis the innumerable examples of human suffering, pain, and suffering in this world in the past, present and – probably – future? If God can prevent all suffering and evil, but does not do so, then God is not all-good. If God wants to prevent evil and suffering, but cannot do so, then God is not all-powerful.

In response to this dilemma, Christian theologians have developed what is known as theodicy (Greek: theos, ‘God’; dike, ‘justice’; ‘to do God justice’): a theological attempt to defend God’s goodness and omnipotence in the face of evil. Within the Christian tradition at least five major types of theodicies can be identified:

Irenaean Theodicies. Named after Irenaeus of Lyon, these theodicies argue that evil and suffering serve a pedagogical or developmental purpose, a ‘greater purpose’. According to this view, upheld in different forms by Origen of Alexandria, Gregory of Nyssa, and Maximus the Confessor, evil and suffering are necessary for spiritual growth, for proving loyalty to God, as a form of just punishment for sin, or as a ‘blessing in disguise’. Furthermore, this perspective acknowledges that God’s ways and reasons may be beyond human understanding.

Augustinian Theodicies. Rooted in the writings of Augustine, this approach views evil not as a created substance but as a privation of the good (privatio boni). Evil, in this view, enters the world through the misuse of free will granted by God to angels and humans alike. Thus, God is not the author of evil; rather, evil is the result of creatures turning away from divine order. This theodicy deeply influenced Western Christianity and underlies the soteriological logic of redemption as a return to God’s goodness.

Process Theodicies. Emerging from process theology, developed by Alfred North Whitehead and elaborated by Charles Hartshorne and John B. Cobb Jr., this view posits a dipolar understanding of God: God is not an unchanging, omnipotent monarch but a relational and temporal being who co-evolves with creation. God’s power is persuasive rather than coercive, working with the inherent possibilities and freedom of the world. Consequently, God is not culpable for evil in a deterministic sense but suffers with the world and seeks to lure it toward greater beauty and order.

Cruciform Theodicies. Influenced especially by Moltmann, this view emphasizes that God suffers with creation. God is not distant or indifferent but has entered into the depths of human suffering in the crucified Christ. This theodicy also draws on Dorothee Sölle (1929–2003), who framed divine suffering in political and liberationist terms, and Kazoh Kitamori (1916-1979), who saw divine pain as the very heart of reconciliation. This approach reframes divine omnipotence as kenotic (self-emptying), highlighting God’s solidarity rather than sovereignty.

Anti-Theodicies. Represented by theologians such as Emil Fackenheim (1916–2003) and Jean Améry (1912–1978) in response to the Holocaust, and later by thinkers such as Marcia Falk (1946), Richard Rubenstein (1924-2021), and David Bentley Hart (1965), this perspective refuses to rationalize or justify evil. It asserts that some forms of suffering, such as genocides, famines, or natural disasters, are so grotesque and absolute that they defy all theological explanation. The attempt to ‘defend God’ in the face of such horrors may itself become morally suspect. While some proponents retain belief in God, they argue that this belief must be radically revised in light of historical trauma.

Each of these approaches attempts, in its own way, to grapple with the profound mystery of how to understand God’s nature in light of the undeniable presence of evil and suffering in the world. This ongoing theological struggle reflects one of the most enduring and complex questions in Christian thought.

7. On being human: nature, sin, and grace (theological anthropology)

Earlier (Chapter II.4), we addressed the question of precisely what humanity needs to be saved from, through the cross and resurrection of Jesus Christ. The answer to this question is closely tied to the Christian understanding of what it means to be human and/or what humanity has become. At the core of Christian anthropology lies the conviction that humans are created in the image and likeness of God (imago Dei), meaning that God and humans share a certain resemblance. Already in the second century, Irenaeus emphasized this idea in his doctrine of recapitulation, arguing that Christ comes to restore what was lost in Adam. Over time, theologians such as Augustine, Thomas Aquinas, and more recently Barth and Rahner explored the imago Dei in terms of relationality, rationality, freedom, and capacity for divine self-transcendence.

Humanity’s original, pure identity was lost due to the misuse of free will, which led humans to act against God and his commandments. The sin of Adam and Eve, as described in Genesis 3 being their disobedience to God’s command, is understood as the ‘first sin’. Every individual human sin is linked to this primal transgression and is referred to as ‘original sin’. Two main theological positions have developed regarding this: either all humans sinned in Adam and Eve’s act (collective guilt), or every person sins individually as Adam and Eve did (individual repetition or confirmation of original sin).

Augustine was the first to develop the doctrine of peccatum originale in a systematic way, particularly in his writings directed against the monk Pelagius (early 5th century) and his followers. Augustine argued that the guilt of Adam is transmitted through human generation, emphasizing collective guilt and humanity’s inability to turn toward God without grace. In contrast, Pelagius rejected this, insisting that individuals have the moral capacity to choose the good without inherited sin. In later centuries, Peter Abelard and others offered more moralistic or individualistic interpretations, while Martin Luther and Calvin (arguing against Erasmus of Rotterdam) reaffirmed Augustine’s emphasis on total depravity and the need for divine grace.

Historically, the doctrine of original sin was often interpreted physiologically, connecting it with sex, lust, and procreation. However, in modern theology, it has also acquired a more sociological, psychological, and ethical dimension, which might be described today as ‘intergenerational responsibility’. This means that each individual is born into a world already ‘tainted’ by the sins of their ancestors, inheriting a condition or environment affected by prior wrongdoing. Even more, psychologically speaking, every human being is a combination of good and evil inclinations, thoughts, deeds, and words.

The nature of sin has been analogized in various ways within Christian thought. In Christian tradition, the concept of ‘grace’ is central to the understanding of how God works to save humanity from its self-chosen sinfulness. Two key concepts compete for primacy within the Christian tradition: undeserved grace given by God (gratia gratis datur; Latin: ‘grace is given freely’) and merit (meritum), the worth or value of human actions that are deemed by God as deserving of a reward, particularly in relation to salvation and sanctification.

Augustine offers a well-known tripartite classification of grace. (1) Prevenient grace (gratia praeveniens) meaning that God is already active within people even before they convert, want to convert, or know they want to convert. (2) Operative grace (gratia operans) meaning that God converts people without their active cooperation. And (3) cooperative grace (gratia cooperans) meaning that, after conversion, God and humans work together toward the person’s sanctification. This latter dynamic would become a central tenet of Thomas Aquinas, who held that grace perfects nature and that the human will, moved by grace, can freely cooperate with God’s sanctifying work. The Council of Trent (1545-1563) would later formalize this teaching against Protestant claims of justification by faith alone (Latin: sola gratia).

Another distinction is between gratia sanans (‘grace that heals’) and gratia elevans (‘grace that elevates’). The first liberates people from sin, and the latter elevates individual believers above their initial created status, a process known as ‘deification’.

8. On the sacraments: material elements, spiritual graces (sacramental theology)

In Christian tradition, especially in the Eastern Orthodox, Anglican, and (Roman) Catholic traditions, a sacrament is defined as a ‘physical or material element presented to the external senses, which represents an invisible, spiritual grace by means of resemblance, signifies it by institution, and encompasses it by sanctification’ (as Hugo of St. Victor defined) (see Chapter I.6). This classic medieval definition builds on the patristic insights of Ambrose of Milan, who emphasized the mysterious transformation of the elements, and Augustine of Hippo, who described sacraments as ‘a visible sign of an invisible grace.’ Pope Leo the Great described the sacraments as: ‘What was visible in our Savior has passed over into his mysteries’. The word ‘mystery’ (Greek: mysterion) does not mean ‘something puzzling or mysterious’, as in modern English, but something ‘concealed’ from ordinary perception.

From this definition, it follows that sacraments contain four essential components:

Physical element: The sacramental action must include something tangible and perceptible (e.g., water in baptism or bread and wine in the eucharist), echoing Thomas Aquinas’ affirmation that the material elements are necessary for our sensory-based human nature.
However, this physical element should be accompanied by a verbal formulation; as Augustine stated in his famous adage, Accidit verbum ad sacramentum ad elementum et fit sacramentum, ‘when the word is added to the element, it becomes a sacrament’.

Resemblance (symbolic analogy): There must be a (symbolic) similarity or likeness between the physical element and what it signifies. This is rooted in Gregory of Nyssa’s notion that material things can point toward spiritual realities. For instance, water symbolizes the washing away of sins; wine resembles the blood of Christ shed on the cross.

Valid institution: There must be a (usually implicit) connection to the “institution” of the sacrament by Jesus Christ in the New Testament. Examples include Jesus’ own baptism in the Jordan and the Last Supper.

Efficacy (effectiveness): Sacraments accomplish what they signify. For example, the water of baptism not only symbolizes the washing away of sins but actually effects that cleansing.

A sacrament considered valid needs, at the very minimum, the ‘intention to do what the Church does’ of the minister as well as of those receiving it,. The minister must intend to perform a sacramental rite as the Catholic Church understands it, even if he personally doubts its theology.

‘Ex opere operato’

During the so-called Donatist controversy in Early Church history (4th–5th century), a major debate arose concerning the conditions under which sacraments are valid and effective. The Donatists, a rigorist movement originating in North Africa after the Diocletian persecution, contended that sacraments derive their efficacy from the personal holiness or moral integrity of the minister administering them (ex opere operantis). This view was rooted in their belief that clergy who had lapsed during persecution (traditores, ‘traitors’) could not validly perform sacramental acts.

This is in contrast to Augustine’s articulation (what would become the default orthodox position) that sacraments are effective ex opere operato, that is, by virtue of the sacramental act itself, provided it is performed with the correct intention and form, and within the Church. According to Augustine, the true minister of every sacrament is Christ himself, who operates through the sacramental signs regardless of the unworthiness of the human minister. This position was reaffirmed by Thomas Aquinas and later dogmatically codified at the Council of Trent (1547) in response to Reformation critiques.

Sacraments fulfil several important theological and ecclesial functions. (1) They mediate divine grace to believers, as emphasized by Irenaeus of Lyon and Cyril of Jerusalem (313-386), who saw sacraments as tangible means of divine life. (2) They strengthen the faith of believers in God, a point stressed by Anselm of Canterbury and Martin Luther, who understood sacraments as confirmations of God’s promise. (3) They enhance the unity and communal involvement of believers within the Church, as emphasized by Henri de Lubac. (4) They confirm God’s promises to the faithful, in continuity with John Calvin, who described sacraments as ‘seals’ of divine promises and Karl Rahner, who highlighted their eschatological dimension. Thus, the sacramental tradition developed both a robust theological anthropology and ecclesiology, in which divine action, human participation, and ecclesial mediation coalesce in ritual practice.

The sacrament of the eucharist

Two sacraments, baptism and the eucharist have been the focus of significant theological debate. Here are some examples of such discussions. From the earliest days of the Church, the eucharist, alongside baptism, occupied a central place in ecclesial life (cf. 1 Corinthians 11:20-27). This involves the breaking and sharing of bread and wine as instituted by Jesus Christ and commanded to be continued in his name. Early theology affirmed the real presence of Christ in this sacrament, that Christ is truly present (praesentia realis). The theological question then became: how should this presence be understood?

The dominant Catholic theological model is transubstantiation. This doctrine holds that while the accidents (the appearances or forms) of bread and wine remain unchanged, their substance (the underlying reality) is transformed into the Body and Blood of Christ. Since the Enlightenment, this Aristotelian metaphysical framework has been challenged due to incompatibility with modern scientific understanding. Alternative theories have been proposed, such as: transfinalization (a change of purpose or final cause, cf. Edward Schillebeeckx), transignification (a change of meaning or signification, cf. Karl Rahner), or consubstantiation (the idea that bread and wine coexist simultaneously with the Body and Blood of Christ, cf. Martin Luther).

The sacrament of baptism

Baptism has also been a subject of vigorous debate, particularly regarding whether it should be administered to infants (paedobaptism) or only to adults (believer’s baptism). The New Testament records entire households being baptized, which presumably included children. By the 2nd century, infant baptism was widely practiced, although the historical reasons are complex, with pastoral concerns likely playing a key role.

Cyprian of Carthage defended infant baptism in the third century, arguing that all humans, regardless of age, are born with original sin and therefore require the grace of baptism. Augustine of Hippo later developed this into a more elaborate theological anthropology, distinguishing between the culpa (‘guilt’) of original sin, remitted in baptism, and its concupiscentia (‘concupiscence’, or spiritual disorder), which persists and must be resisted throughout life. This led to the widespread belief that unbaptized infants could not attain salvation, a view that prompted later reflection. For instance, Thomas Aquinas, while upholding Augustine’s position, suggested that unbaptized infants might exist in a state of natural happiness without the beatific vision (limbus infantum), a view also echoed by Peter Abelard.

On the other side, the Anabaptists of the 16th century, such as Balthasar Hubmaier (1485-1528) and Menno Simons (c. 1496-1561), argued for believer’s baptism, claiming that baptism must be a conscious act of faith and repentance, not something passively received in infancy. This position was sharply opposed by John Calvin, who defended paedobaptism by emphasizing the continuity of God’s covenantal dealings with believers and their children.

9. On the Church: a saintly challenge (ecclesiology)

The Church is the visible community of those who believe in Christ, referred to in biblical terminology, especially by Paul, as the ‘Body of Christ’, with Christ himself as its head (cf. 1 Corinthians 12; Ephesians 4:15–16). ‘The Church’ refers to the holy and perfect Church of Christ himself (ecclesia invisibilis, or ‘invisible church’) and to the earthly, institutional Church (ecclesia visibilis, or ‘visible Church’), with its rules, authorities, and protocols. The extent to which these two, the invisible Church of Christ and the concrete, historical Church (or Churches), are connected (whether they overlap fully, partially, or not at all) is the subject of significant theological debate. Augustine of Hippo argued that the visible Church contains both the saved and the unsaved (the corpus permixtum, or ‘mixed corpus’), whereas Donatist thinkers insisted on a visible Church of only the pure.

In the Nicene-Constantinopolitan Creed (381), the Church is described with four attributes (notae ecclesiae, ‘ecclesial notions’): she is one, holy, catholic, and apostolic. Unity (una) reflects the Church’s ontological unity in Christ, despite human divisions, a theme stressed already by Cyprian of Carthage in his famous ‘he can no longer have God for his Father who has not the Church for his mother’. Holiness (sancta) is both a gift and a vocation: the Church is made holy by God but must also grow into holiness, a point underscored by theologians like Gregory of Nyssa and especially by Vatican II. Catholicity (catholica) refers to the Church’s universal mission and scope, a concept developed by Ignatius of Antioch, who first used the term ‘Catholic Church’. Apostolicity (apostolica) denotes continuity with the apostles, safeguarded through apostolic succession, a position emphasized by Irenaeus of Lyon and reaffirmed by Thomas Aquinas in his discussion of ecclesial authority.

Church modes

Since Pentecost, the Holy Spirit has been the fundamental principle of Christ’s abiding presence in the Church. Through the Spirit’s indwelling and activity, Christ becomes sacramentally, liturgically, and communally present to the faithful in concrete and discernible ways. The Second Vatican Council offers a particularly good articulation of these modes: in Sacrosanctum Concilium, the Council identifies five forms in which Christ is truly present in the Church’s liturgical life:

in the eucharistic species, in an exceptional way;

in the person of the minister;

in the sacramental actions (Christ himself baptizes, absolves, and consecrates);

in the proclamation of Scripture; and

in the assembled Church, gathered in worship.

A second set of ecclesiological dimensions is provided by another document of the Second Vatican Council: Lumen gentium, which describes the Church as:

6. a communion (Greek: koinonia, Latin: communio) of believers gathered around Christ, a perspective later developed by Jean-Marie Tillard (1927-2000) and Joseph Ratzinger;
7. the People of God on pilgrimage through history, a biblical image central to the ecclesiologies of Karl Rahner and Edward Schillebeeckx;
8. a charismatic community, enlivened by the Spirit’s gifts (charismata), as explored by Hans Urs von Balthasar and Jürgen Moltmann.

Placed within this broader pneumatological context, the Council’s teaching can be read as a unified vision: the Holy Spirit makes Christ present in five concrete liturgical modes (Sacrosanctum Concilium 7) and simultaneously shapes the Church’s identity as communion, pilgriming people, and charismatic body (Lumen gentium). Thus, the reflection both begins and ends with the Spirit, who enables the Church to encounter, embody, and proclaim the presence of Christ.

10. On the various religions: blessing or problem? (theology of religion)

The theology of religions studies the question of how, from a Christian perspective, the existence of other religions should be theologically evaluated. While early Christian thought focused largely on Judaism, Greco-Roman polytheism, and later Islam (often seen as a Christian heresy by medieval theologians like John of Damascus), the question became historically urgent during the era of European exploration and colonization. For the first time, Christian missionaries and explorers encountered entire civilizations in Africa, Asia, and the Americas whose members had never heard of Christ. The traditional assumption of the universality of Christianity, at least within Europe, was deeply challenged by the religious plurality of the world. Within Christian theology, four broad models have emerged to describe the possible relationship between Christianity and other religions: exclusivism, inclusivism, pluralism, and particularism. Each comes with its own theological foundations, internal tensions, and key representatives.

Exclusivism

At one side of the spectrum, we have a position called exclusivism. This idea asserts that salvation is available through, and only through, explicit faith in Jesus Christ and often, more specifically, through membership in the institutional Church. This position draws upon the Early Church dictum attributed to Cyprian of Carthage: extra ecclesiam nulla salus (Latin: ‘outside the Church there is no salvation’). It was maintained and developed by figures such as Augustine of Hippo, who argued that while God’s grace is primary, it is ordinarily mediated through the sacraments and ministry of the Church. In modern Catholic theology, this position was prevalent until the mid-20th century and was formalized in documents such as Pius IX’s encyclical Quanto conficiamur moerore (1863), which expressed hope for the salvation of the ‘invincibly ignorant’ but maintained the necessity of the Church. Exclusivism faces serious theological questions, such as the fate of the unevangelized (those who have never heard the gospel), and whether this view does justice to God’s universal love and mercy. It also risks making salvation overly dependent on historical contingency, language, or geography.

Pluralism

On the other side of the spectrum, we find religious pluralism, a position favored by many people in the 21st century. It contends that all major and minor religious traditions are valid paths to the divine or to salvation. This view was articulated most clearly by theologians such as John Hick (1922-2012), who proposed a ‘Copernican revolution’ in the theology of religions: instead of seeing Christianity as the center, all religions should be viewed as orbiting the same divine ‘Real’. For Hick, different religions are culturally conditioned responses to the same ultimate reality. Paul Knitter (1939) and Raimon Panikkar (1918-2010) also belong to this school of thought, each proposing dialogical models that affirm the positive theological value of non-Christian traditions.

While pluralism is attractive in its spirit of openness and inclusivity, it faces critical objections. Theologically, it relativizes the unique role of Christ and the specificity of revelation. Joseph Ratzinger (Pope Benedict XVI), among others, warned that pluralism risks collapsing theological truth into mere sociological preference. Moreover, the idea of a meta-perspective from which one can judge all religions equally, an implicit assumption in many pluralist theologies, has been questioned on philosophical grounds by thinkers such as Gavin D’Costa (1958), who argues that such a neutral standpoint is illusory and itself rooted in a particular worldview.

Inclusivism

Inclusivism occupies a middle position between exclusivism and pluralism, and has become the default position in at least the (Roman) Catholic tradition. It maintains that Jesus Christ is the universal and normative means of salvation, but that this salvation can be extended to those outside explicit Christian faith. This position was notably advanced by Karl Rahner, who introduced the idea of the anonymous Christian, a person who, without explicit knowledge of Christ or the Church, nevertheless responds to God’s grace and thus participates in the mystery of salvation through Christ. Rahner’s model gained much influence during the Second Vatican Council, especially in Lumen gentium (1964) and Nostra aetate (1965). The first stated that those who, ‘through no fault of their own,’ do not know the gospel may nevertheless achieve salvation if they sincerely seek God and follow their conscience. The latter explicitly speaks positively about non-Christian religions, especially Judaism and Islam. Hans Urs von Balthasar also upheld the universality of Christ’s saving work but stressed the mysterious nature of God’s judgment and the hope that all might be saved.

Critics of inclusivism, however, argue that it can amount to a form of religious imperialism, implicitly reducing other religions to incomplete or unconscious forms of Christianity. From the perspective of non-Christian religions, the idea that their faithful are ‘anonymous Christians’ can seem patronizing and dismissive of their own theological integrity.

Particularism

In recent decades, some theologians have sought to move beyond the ‘old’ threefold typology. Stephen Mark Heim (1950), for example, proposes a ‘multiple salvations’ model in which different religions aim at different spiritual ends, while thinkers such as Amos Yong (1965) explore pneumatological and Trinitarian approaches that allow for a broader theological engagement with religious diversity. Bottom of Form

11. On the search for the hidden God (theology of culture)

Closely connected to the theology of the religions, is the question of a theological appraisal of everything not explicitly Christian. This question already arose in the beginning of the Christian tradition, when the young Jesus-movement came into contact with Greek philosophy, a dominant intellectual force in the Roman Empire of the first centuries. Being blatantly of non-Christian origin, the philosophies of Plato and the philosophical language of his fellow Hellenistic thinkers were nevertheless very helpful in reflecting upon the Christian faith and highly advantageous for the promotion of the faith among non-Jewish ‘gentiles’.

This issue re-emerged in the context of the discovery and colonization of the ‘New World’, and especially in the context of the Western secularization of the 20th century. In the first context, Christians came into contact with various civilizations all over the world (see also the previous chapter), all having developed their own culture and society without any apparent need for the Christian faith. In the second context, modern secular society seems to care little for institutional religion (see the Introduction at the beginning of this book), and is nevertheless able to establish quite an impressive cultural reservoir.

In discussion with Hellenistic philosophy

In the context of the discussion with the Greco-Roman culture, theologians like Justin Martyr and Augustine found theological solutions to this problem. Justin wrote about logoi spermatikoi (Greek: ‘seeds of the word’), the idea that God sowed his grace and self-revelation lavishly over all peoples, cultures, religions, and civilizations. Jesus Christ, as the incarnated logos, is – however – the highest truth, that is, the ‘place’ where God’s self-revelation reaches its climax.

Augustine, borrowing from Philo of Alexandria (c. 20-c. 50), used the idea of the Spolia Aegyptiorum (Latin: ‘the Egyptian spoils of war’). In Exodus 3:21-22, God orders the Israelites, who appear to be able to flee from Egypt after all, to ‘plunder the Egyptians’, that is, to take their gold and silver with them into the desert and on to the Promised Land. In Augustine’s exegesis, this Egyptian silver and gold is ‘tainted’ by their previous dedication to the idols of their homeland. Nevertheless, so Augustine argues, the Israelites did make use of these ‘spoils’, either to honor and praise God – by decorating the Tabernacle (thought to be God’s dwelling place among the people) – or to erect false idols – by creating the infamous statue of the Golden Calf (or bullock). Augustine argues, thus, that it is the purpose that matters, not the origin. Just as the Israelites used Egyptian gold to honor God, so Christian theology can use Greek philosophy to contemplate Christian truths more thoroughly.

In discussion with the cultures of the New World

Another notion used in this context is the praeparatio Evangelica (Latin: ‘the preparation for the gospel’). It suggests that other, non-Christian things, notions, and ideas can have theological merit, because they prepare the not-yet-Christians for initiation into the ‘true’ religion. It links up to Justin’s idea of the logoi, in the sense that God already sowed the ‘other’ cultures with ideas, insights, and revelations that would be understood in their completeness once interpreted in an explicitly Christian context. Executed in the context of Western colonization, this approach seems to be ‘imperialistic’ (see the concept of the ‘anonymous Christian’ in the previous chapter), but it, nevertheless, ensured that the adherents of this idea would not destroy the indigenous cultures and materials, but keep them for further study, and appreciate their propaedeutic function.

The idea of the praeparatio coincides historically with Ignatius of Loyola’s (the founder of the Jesuit Order) famous phrase ‘seek God in all things’ (Latin: Deus in omnibus quaerere). It expresses the conviction that God is present and active in every aspect of creation, not only in explicitly religious contexts. It is not coincidental that Jesuit missionary activities in the New World were often in the form of inculturation. Inculturation is the dynamic and reciprocal process by which the Christian faith is expressed and lived within a particular culture, allowing the gospel to take root in local symbols, values, and practices while also transforming them.

In discussion with secular culture

In modern days, the 20th and 21st centuries, we again find new concepts. Jürgen Moltmann’s notion of implicit theology emphasizes the presence of theological meaning within human experiences, cultural expressions, and historical events, even when these are not explicitly religious. He argues that theology must be attentive to the hidden traces of divine revelation in the secular world, particularly in the cries for justice, peace, and human dignity. Similarly, Paul Tillich distinguishes between a theology of the Church, which remains within doctrinal boundaries, and a theology of culture, which seeks to interpret the ‘religious substance’ present in cultural phenomena. For Tillich, this substance refers to the depth dimension of human existence, as well as to the ultimate concern that underlies art, philosophy, politics, and popular culture, and which theology must engage with if it wants to remain meaningful in the modern world.

This approach resonates with the Second Vatican Council’s call (in Gaudium et spes) to read the signs of the times (Latin: signa temporum) as places where God speaks through contemporary history. The Council encourages the Church to engage the world in a spirit of discernment and solidarity, recognizing the presence of grace even amid secularity and suffering. However, the Vatican’s International Theological Commission later acknowledged that the Church has often interpreted these signs too late, responding belatedly to social upheavals, scientific developments, or moral challenges.

12. On the Last Things: judgment and apocalypse (eschatology)

The doctrine of the ‘last things’ (Greek: ta eschata) is called eschatology, and is divided into individual eschatology and collective eschatology. The first focuses on the fate of individuals after their death, while the latter is concerned with the whole of creation at the end of time, the ‘resurrection of the body’ (the individual and corporeal resurrection of this individual believer), the Last Judgment (passed on the whole of creation by Jesus Christ), and the existence of heaven and hell.

Eschatological discourse does not only concern a transcendent reality (difficulty #1), but also a moment in the future that cannot be precisely determined (difficulty #2). Sometimes the word ‘Apocalypse’ or ‘apocalyptic’ is used synonymously, but this term refers to a literary genre, especially associated with the last book of the New Testament called Revelation (Greek: apokalypsis, ‘unveiling’ or ‘revelation’). Eschatology is always related to the realization of the Kingdom of Heaven, the perfect world that Christ came to proclaim. This realization exists in the tension between ‘already’ (in Christ) and ‘not yet’. For the apostle Paul, the life, suffering, death, and resurrection of Jesus Christ marks the beginning of a ‘new era’ in which God reigns. In fact, humanity has been ‘in the end times’ since Christ’s resurrection.

Theological thinking about life after death is also part of these discussions. The first discussion concerns the relationship between the particular judgment (immediately after a person’s death) and the final judgment (for all people at the end of time). The second discussion concerns the possible outcomes for a person after one or both judgments. Christians generally share the idea of heaven (for the righteous) and hell (for the unrighteous). Catholics and Eastern Orthodox believe that purgatory lies ‘in between’, where the vast majority of deceased believers end up, since most people are neither truly evil nor perfectly good. Purgatory allows for the purification of the soul so it can ultimately enter heaven. However, there are theological critiques of the concept of hell: the existence of eternal damnation appears to contradict the Christian confession of God’s ultimate victory over evil.

Two related terms are also relevant in the history of eschatology: the Limbus patrum (‘the limbus of the fathers’) the ‘intermediary space’ where the (of course unbaptized) ‘saints of the Old Testament’ (Abraham, Moses, etc.) waited until they were redeemed by Christ, a non-biblical event known as the descensus Christi ad inferos (the ‘descent of Christ into the underworld’, in English also known as ‘the harrowing of hell’); and the Limbus infantum (‘the limbus of the infants’), a kind of ‘space’ where unbaptized children were thought to dwell and enjoy a kind of natural bliss, outside heaven itself. In 2007, Pope Benedict XVI, on the advice of the Vatican’s International Theological Commission, expressed the hope that, due to God’s infinite mercy, the unbaptized children would nevertheless experience heaven proper.

Conclusion. And now the real work begins!

This book was never meant to be the final word; it is a beginning. Theology is not simply a matter of mastering facts, memorizing doctrines, or quoting Scripture and Church Fathers. It is a way of life. And like any way of life, it requires both discipline and delight, both curiosity and commitment.

Read a lot. Theology is nourished not only by academic books and ecclesial texts, but also by the arts and by popular culture. A good theologian reads the Bible, the Church Fathers, and Vatican documents (as much as possible in the original languages), but also listens to pop songs, plays games, and watches films. Attentively! Everything can be a text. Everything can be a source of insight. Everything, if read theologically, can speak of God.

Question everything. There are no stupid or ‘heretical’ questions in theology, only questions not asked. Even the most basic or challenging inquiry can be the beginning of deeper understanding. Doubt is not the opposite of faith, but often its necessary companion.

Reflect often. Theology without self-reflection becomes sterile. Ask yourself: What do I believe, and why? Where do I come from? What experiences shape my perspective? Where are my blind spots? This kind of critical honesty to oneself, and the religious tradition one has been brought up in, is not weakness but strength.

Write constantly. Theological insight is forged in writing: through drafts, experiments, failures, and revisions. As the saying goes, ‘A master has failed more times than a student has tried.’ Writing is not just the result of thinking but a way of thinking.

Meditate regularly. Theology is not only rational reflection. It is also an encounter with mystery. The subject of theology is God, and God exceeds our grasp. Make room for silence, awe, prayer, and even prolonged unknowing.

Celebrate persistently. Theology demands a liturgical and sacramental grounding. Without participation, whether in religious celebration or other forms of spiritual practice, faith becomes abstract. Doctrine without doxology is dead.

Share abundantly. Theology does not belong to the scholar alone. It wants to be shared, discussed, challenged, lived. A theology that is not communicated is a theology not yet fully realized.

So, take up your reading. Ask your boldest questions. Reflect without fear. Write with passion. Make time for wonder. Join the celebration. And do not forget to share what you have found. The real work of theology begins now, hopefully also with you.

Appendix I: Dutch church history

Since I am writing this little book within the context of my work for the Tilburg School of Catholic Theology (the Netherlands), it feels fitting to include a small paragraph on the particularities of Dutch church history, in all its complexity. If you are studying theology in the Netherlands – from wherever you might have come or will return to – you need some very basic understanding of the Dutch Reformation, the foundation of the Old Catholic Church, the process of pillarization (and de-pillarization), the Pastoral Council of the Dutch Church Province (1966-1970), the Conciliar Process (1987-1992), and the foundation of the Protestant Church in the Netherlands (2004).

Starting in 1566 with the ‘Beeldenstorm’ (Dutch: ‘iconoclasm’, literally ‘storm of statues’), the area that is now both Belgium and the Netherlands was one of the earliest and most important stages of the Reformation. The Reformation coincided with (and triggered at least partially) the Eighty Years War (1568-1648) in which Protestant rebels under William of Orange fought for independence from (Roman Catholic) Spanish rule. The Peace of Münster in 1648 cemented Protestant dominance in the northern Netherlands, establishing the Dutch Reformed Church as the de facto state Church and relegating Catholics and non-Reformed Protestants to the status of tolerated or persecuted minorities. Over time, a sharp religious divide emerged between the Protestant North and the Catholic South, notably North Brabant, Limburg, and Flanders. Despite formal equality from 1813 onward, societal leadership remained predominantly Reformed. Only in 1853, did Pope Pius IX reinstall the episcopal hierarchy in the Netherlands.

In the late 17th and early 18th centuries, disputes over Jansenism – a theological movement emphasizing divine grace and moral rigor – contributed to growing tensions between Rome and segments of the Dutch clergy. Archbishop Petrus Codde was accused of Jansenist sympathies and suspended in 1702. After his death in 1710, the Chapter of Utrecht elected Cornelius Steenoven as archbishop in 1723. He was consecrated a year later by Bishop Dominique Marie Varlet without papal approval, leading to excommunication by Rome. In the decades that followed, the clergy of Utrecht maintained their episcopal succession while repeatedly appealing for reconciliation and a general council. The hope for reunion diminished after Rome re-established its own episcopal hierarchy in the Netherlands in 1853. When they were not invited to the First Vatican Council, and the Council decreed the dogma of papal infallibility, the schism with the Old Catholic Church of the Netherlands became definite. Several international groups of Catholics, particularly in German-speaking regions, held the same beliefs after the Council. They broke with Rome and aligned themselves with the Utrecht Church, forming the Union of Utrecht in 1889.

In the 20th century, the Netherlands became internationally known for the phenomenon of verzuiling (‘pillarization’), a system in which society was divided into separate religious and ideological pillars, Catholic, Protestant, socialist, and liberal, each with its own institutions like schools, media, unions, and political parties. While scholars debate whether this system arose from emancipation movements or elite control, it led to a remarkably stable political structure. From the 1960s onward, however, this pillarized system rapidly declined as Dutch society secularized, becoming increasingly diverse, tolerant, and religiously indifferent, a process known as ontzuiling (‘de-pillarization’).

During and after the Second Vatican Council, the Dutch church province became predominantly progressive, embracing the Council’s liturgical and theological changes whole-heartedly, even though some conservatives might argue they did so too fervently as well. A good example of this spirit of aggiornamento (Latin: ‘update’) was the ‘Pastoral Council’ (Dutch: ‘Pastoraal Concilie’) of Noordwijkerhout, a nationwide Roman Catholic assembly held from 1966 to 1970, with plenary sessions convened in the town of Noordwijkerhout, and initiated by Cardinal Alfrink. The Council proposed bold innovations such as the possibility for priests to marry and the abolishment of mandatory celibacy, moves that conflicted with Vatican directives and ultimately rejected by Pope Paul VI. While it represented a lively experiment in democratizing church structures – allowing laity and bishops to deliberate as equals – it ultimately generated deep tension within Dutch Catholicism and is frequently cited as a catalyst for post‑1960s secularization in the Netherlands. The Synodal Process initiated by Pope Francis in 2021 could be seen as a universal version of that Dutch Council, even though its width and depth still have to be assessed in the long run.

Another influential and significant post-Vatican II phenomenon was the so-called ‘Conciliair Proces’ (Dutch: ‘Conciliar Process’), an ecumenical initiative between 1987 and 1992, led by the Dutch Council of Churches and inspired by a global call from the World Council of Churches to reflect collectively on justice, peace, and the integrity of creation. The aim was to integrate a specific church vision with social ethics, a focus on environmental stewardship, justice, and reconciliation. While in the Netherlands the campaign was enthusiastically received and influenced church-based civic activism and environmental advocacy, its broader momentum waned as spiritual reflection increasingly displaced societal engagement in local congregations.

The May the 8th movement (Dutch: ‘Acht Mei Beweging’) in the Netherlands was a progressive Catholic reform movement active primarily from the early 1980s to the late 1990s. It emerged after Pope John Paul II’s 1985 visit to the Netherlands, and was the expression of the fact that many Dutch Catholics felt that the Vatican was dismissive of local calls for renewal and openness. The movement brought together Catholics who advocated for a more inclusive, democratic, and socially engaged Roman Catholic Church. Its agenda emphasized issues such as gender equality, the role of laypersons in church governance, ecumenism, and a stronger alignment with contemporary social justice concerns. Although it attracted substantial attention and support in the late 1980s, the movement gradually declined in the 1990s due to internal differences, reduced public momentum, and increasing institutional resistance, eventually dissolving in 2003.

Finally, the 2004 foundation of the ‘Protestantse Kerk in Nederland’ (Dutch: ‘Protestant Church in the Netherlands’) deserves attention. It was a merger between the three largest Protestant denominations in the country: the ‘Nederlandse Hervormde Kerk’ (Dutch: ‘Dutch Reformed Church’), the ‘Gereformeerde Kerken in Nederland’ (‘Reformed Churches in the Netherlands’), and the ‘Evangelisch-Lutherse Kerk’ (‘Evangelical Lutheran Church’). This union marked the culmination of decades of ecumenical dialogue and cooperation aimed at overcoming the historical divisions within Dutch Protestantism, many of which stemmed from 19th-century schisms and theological disputes. While the merger was a significant step toward unity, it also met resistance from more conservative factions, leading to the formation of splinter groups such as the ‘Hersteld Hervormde Kerk’ (‘Restored Reformed Church’).

Appendix II: Primers for Tilburg School of Catholic Theology

In this appendix, specifically connected to the study of theology at the Tilburg School of Catholic Theology, I introduce three different ‘codes’ that aspiring students of theology must familiarize themselves with: the academic code (Chapter 1), the theological code (Chapter 2), and the ecclesial code (Chapter 3). To conclude this part, I have included some tips and ‘tricks’ regarding ‘academic hygiene’ (Chapter 4) concerning fraud, citations, and artificial intelligence.

1. The academic code

If you want to study theology at a university, you must have a basic understanding of how things ‘work’ at the academy in general and in academic theology specifically.

Levels of publications

Academia is a place governed by scholars’ publications. For the uninitiated, the various forms of publications are overwhelming, especially since everybody working in academia assumes implicitly that this is already understood, even if nobody has ever explained matters in full detail.

Primarily, we distinguish three levels of publications based on their intended audience(s): popular, professional, and academic.

Popular publications are aimed at the general public, using accessible and non-specialized language, and are often journalistic or (partially) entertaining in nature.

Professional publications are aimed at practitioners in a specific (professional) field, and are usually more technical in nature than professional, but not necessarily or typically peer-reviewed.

Academic publications are aimed at scholars and researchers, are typically peer-reviewed, theoretical in nature, and written with methodological rigor. ‘Peer review’ is a quality-control process in which experts in the same field critically evaluate a scholarly work or research proposal before it is published or accepted.

Genre of publications

If we zoom in on the last category of professional publications – the ones students at university will come across the most often – we can differentiate between various genres (see Table 1).

Table 1 – Most common genres of academic publications.

Level | Genre | Author(s) | Editor(s)
Bachelor/Master student | paper/essay | 1/+ | no
thesis | 1 | no
PhD student | thesis (dissertation) | 1 | no
From Post-Doc onwards | journal article | 1/+ | no/yes (guest editor of special issue)
chapter in edited volume | 1/+ | yes
monograph | 1/(+) | no/yes (certain editions)
lemma in encyclopedia | 1/(+) | yes

On the level of Bachelor and Master student, we find written papers and essays, usually in the context of assignments for various courses, authored by one or more students, depending on the specifics of the assignment. On the same level, we find the genre of theses, typically written by one author at the end of their bachelor and master program.

On the level of the PhD student (also ‘Doctoral Candidate’ or promovendus, ‘the person who is to be promoted’), we find – again – the genre of the thesis or dissertation as it is commonly known. The dissertation is typically written by one author and differs from the bachelor and master thesis both in terms of quantity and quality.

On the level of the Post-Doc (short for ‘postdoctoral researcher’) and above, we find the plethora of different academic genres associated with the work of scholars and scientists. The most prominent among them are:

Articles in an academic journal, authored by one or more scholars, typically without the need of an overall editor.

For example: Archibald van Wieringen, ‘Genesis 1-4 as Harmony and Disharmony’, Gregorianum 106/3 (2025), 541-554.

However, sometimes a special issue of an academic journal is under the direction of an editor. The task of this ‘guest editor’ is typically to oversee the selection of the special issue’s content, the selection and communication with invited authors of articles, and the reviewing of all articles (together with other peer reviewers who are not involved in the issue).

For example: a special issue of the journal Religions of April 2019: Frank Bosman (ed.), The sacred and the digital. Critical depictions of religions in video games, special issue Religions, Basel: MDPI.

Chapters in edited volumes, authored by one or more scholars, typically under the editorship of one or more scholars (with the same duties as the guest editor, see above).

For example: Harm Goris, ‘Thomas Aquinas on the Virgin Birth’, in: Marcel Sarot and Archibald van Wieringen (eds.), The Apostles’ Creed: Born of the Virgin Mary, Leiden: Brill (2024), 161-182.

Monographs (‘books’) are typically (but not necessarily) written by one author without the need of an editor, except in certain circumstances, for example when the works of a deceased scholar are bundled and re-published.

For example: Kees de Groot, The Liquidation of the Church, London: Routledge (2017).

Lemmas are very short entries in scholar encyclopedias, typically written by one scholar, under the editorship of one but usually more editors (with the same duties as described above).

For example: Michael Scott Robertson, ‘1 and 2 Timothy’, in: James Crossley and Alastair Lockhart (eds.) Critical Dictionary of Apocalyptic and Millenarian Movements. 28 October 2021, https://www.cdamm.org/articles/1-and-2-timothy [visited December 10, 2025].

Academic hierarchy

The academy has its own hierarchy, which is sometimes confusing for those who are not part of its inner workings. Hereby a concise overview of the Dutch academic hierarchy, from bottom to top.

Bachelor and Master students are enrolled in undergraduate and graduate programs.

PhD students or Doctoral Candidates are researchers working toward a doctorate.

Post-docs (Postdoctoral Researchers) are temporary researchers with a PhD, acquiring academic credentials in various positions, usually at more than one university.

Assistant Professors (Dutch: universitair docent, UD) are usually permanent staff members (or on tenure-track) of a faculty, combining the doing of research and teaching courses.

Associate Professors (Dutch: universitair hoofddocent, UHD) are typically mid-level, usually with a very specific niche research topic.

(Full) Professors are senior academics with all the authority coming with the rank, especially in the Netherlands the ius promovendi, the ‘right to promote people’ to the rank of doctor.

Honorary Professors are professors only in title, awarded for certain merits, often without academic duties or a salary.

Professors by Special Appointment are part-time or externally funded professors with a specific remit.

Endowed Professors are professors appointed with external funding from a foundation or company.

Academic degrees (general)

Academic degrees are also a source of confusion for aspiring students. Here is an overview:

Students who have successfully finished their bachelor or master program may add ‘BA’ or ‘MA’ behind their surname.

For example: John Mickelson MA.

If a student succeeds in successfully defending their dissertation, the abbreviation ‘Dr.’ is placed before the first name.

For example: Dr. John Mickelson (leaving the ‘MA’ out).

If a person is appointed professor (full, honorary, or by special appointment) the abbreviation ‘Prof.’ is placed before ‘Dr’.

For example: Prof. Dr. John Mickelson.

The Roman Catholic Church has its own three-tier system of academic degrees (see below).

Useful online sources (general)

When studying theology in academia, there are a number of very handy, free, online sources and tools. Here is a selection of these sources and tools. The URLs mentioned can – unfortunately – change in the course of time. If a link is broken, please use a search engine to find the site/tool again at its new address.

Useful online scholarly sources in general:

Google Books: a searchable database of books and previews from publishers, libraries, and authors. Useful for finding academic and popular publications. However, most books only have a very limited number of pages freely available.
https://books.google.com

Google Scholar: a search engine for scholarly literature including articles, theses, books, conference papers, and patents. The availability of the material found may be freely available or not, depending on the level of access given to you by your university or organization.
https://scholar.google.com

WorldCat: a global catalogue of library collections that helps locate books and other resources in nearby libraries (either physical or digital publications). Access depends on the level of access given to you by your university or organization.
https://www.worldcat.org

Internet Archive: a digital library offering free access to millions of books, movies, software, and music, usually containing material that has lost its copyright protection.
https://archive.org

Wayback Machine: a tool within the Internet Archive that lets you view archived versions of websites over time; especially handy when a webpage you are looking for is either edited or lost. This is also the reason why you should always give a date of visit to any web source you quote in your scholarly work.
https://web.archive.org

ResearchGate: a professional network for researchers to share publications.
https://www.researchgate.net

Academia.edu: another professional network for researchers to share publications
https://www.academia.edu

Nexus Uni: a gateway to all articles of a large number of Dutch newspapers and journals, including national and regional newspapers, newsmagazines, and professional and financial publications (access only with account provided by the university).
https://advance.lexis.com

For theology-specific online sources, see below.

2. The theological code

Like all academic disciplines, theology has its own specific codes one must abide by.

Academic degrees (ecclesial)

The Roman Catholic Church also has its own system of academic degrees: three degrees in Sacra Theologia (Latin: ‘Sacred Theology’) and two degrees in Scientiae Religiosae (Latin: ‘Religious Sciences’):

Baccalaureatus is a Bachelor’s Degree, slightly surpassing a bachelor degree of Catholic theology (with very specific courses).

Licentiatus is a Licentiate’s Degree, usually attained halfway through one’s PhD research. It is required for teaching in seminaries.

Doctor is a Doctoral degree (only for Sacra Theologia), the highest ecclesial academic degree.

Ecclesial degrees, like STB, STL, and STD, are placed behind one’s surname, usually in combination with secular ones (see above).

For example: Dr. John Mickelson STD.

Publications by the magisterium

For (Catholic) theology, a special category of publications is issued by the magisterium. An overview of the most important ones:

Church Council Documents (issued by an Ecumenical Council):

Constitutions on various theological issues and notions; regarded as the highest genre of ecclesial documents.

For example: Lumen gentium, the dogmatic constitution on the Church by the Second Vatican Council.

Decrees usually setting forth norms or regulations for the Church.

For example: Unitatis redintegratio, the decree on ecumenism by the Second Vatican Council.

Declarations are typically statements on specific topics.

For example: Gravissimum educationis, the declaration on Christian education by the Second Vatican Council.

Papal Documents (issued by an individual pope):

Apostolic Constitutions are legal in nature and their content is binding and obligatory.

Encyclicals are pastoral letters addressed to all Catholics, often addressing important social or religious issues.

For example: Laudato Si’, on the ‘care of our common home’ by Pope Francis.

Apostolic Exhortations are papal reflections on particular topics addressed to the clergy and faithful, usually connected to a bishops’ synod.

For example: Verbum Domini, on the word of God in the life and mission of the Church by Pope Benedict XVI.

Motu Proprio are legislative letters issued by the pope on his own initiative.

For example: Dolentium hominum, on the founding of the Pontifical Council for the Pastoral Care of Health Care Workers by Pope John Paul II.

Apostolic Letters addressed to specific groups or responding to particular needs.

Apostolic Decrees containing papal decisions related to discipline and administration.

Other Documents can be issued by a bishops’ synod, a bishops’ conference, and individual bishops.

The title of magisterial documents is usually taken from the first two or three words of the Latin text; therefore, the title does not necessarily reflect its content proper. Quotations take the form of the Latin title, followed by the number of the paragraph. If it is a well-known document, it can be abbreviated.

For example: Lumen gentium 14, or LG 14.

The website www.vatican.va has a large archive on magisterial documents, usually in more than one modern language.

Bible (and other classical literature)

Using biblical quotations follows a standardized referencing system to identify specific books, chapters, and verses in the Bible. This system enables readers across languages and traditions to locate passages quickly. A biblical citation typically includes three elements:

. the name of the book (e.g., Genesis or Matthew),
. the number of the chapter, and
. the number of the verse.

For example: John 3:16 refers to the Gospel of John, chapter 3, verse 16.

More difficult situations can occur when citing more than one verse:

A passage covering multiple verses is cited as Genesis 1:1-3 (chapter 1, verses 1 to 3).

If the citation spans multiple chapters, it may appear as Genesis 1:31-2:3 (from chapter 1, verse 31 to chapter 2, verse 3).

If a citation spans multiple combinations between chapters and verses within one book, it may appear as Genesis 1:31-33; 3:2-3 (from chapter 1, verse 31 to verse 33 and from chapter 3, verse 2 to verse 3).

All modern Bibles in all translations use the same standardized division of the books, chapters, and verses. If a Bible verse is given, there is no need to specify which translation one is using. If a Bible verse is quoted, the translation used has to be given.

For example: ‘In the beginning God created the Heaven, and the Earth’ (Genesis 1:1, KJV 1611); where ‘KJV’ stands for the King James Version of the Bible.

Just like the Old and New Testament, literature from the early, medieval, and early-modern theologians have standardized divisions of the work (books, chapters, and (possibly) sections), not page numbers (since they differ from edition to edition). Of course, if one uses a translation, that should be quoted.

For example: ‘Confessiones 10.27.38’ means Book 10, Chapter 27, Section 38 of Augustine’s Confessions.

If you want to use Hebrew and Greek fonts in Word (or another text-editing software program), downloading the (legal and free) fonts at the Society of Biblical Literature is recommended: https://www.sbl-site.org/resources/fonts.

Useful online sources (theology)

Useful online scholarly sources for theology specifically:

Scripture 4 All: a site providing a Greek (for New Testament) and Hebrew (for Old Testament) interlinear Bible, that is translated word-for-word.
https://www.scripture4all.org

The Apostolic Bible Polyglot: a site providing an interlinear translation Greek-English of the Septuagint.
https://apostolicbible.com

The Five Gospels Parallels: a site providing a synopsis of the four canonical Gospels, the Letters of Paul, and the Gospel of Thomas.
https://sites.utoronto.ca/religion/synopsis

The Blue Letter Bible: provides a host of modern Bible translations in many modern languages, the original Hebrew and Greek texts of Old and New Testament, and the texts of the Greek Septuagint and the Latin Vulgate.
https://www.blueletterbible.org

Society of Biblical Literature: free download of (Biblical) Hebrew and (Koine) Greek fonts for text editing programs.
https://www.sbl-site.org/resources/fonts

Magisterium AI: an online AI tool specifically designed to use magisterial documents, theological sources, and Bible translations and commentaries. (For theology, academia, and A.I., see below).
https://www.magisterium.com.

For general online sources, see above.

3. The ecclesial code

Theology is, as I have discussed earlier, always ‘done’ from a denominational perspective, vis-à-vis religious studies which takes an outsider’s (non-denominational) perspective. Christian theology is, therefore, always tied to a specific branch of Christianity. In the Netherlands, for example, we have the Protestantse Theologische Universiteit (Dutch: ‘Protestant Theological University’) that is tied to and trains ministers-to-be for the Protestantse Kerk in Nederland (Dutch: ‘Protestant Church in the Netherlands’). Another one is my own Tilburg School of Catholic Theology, tied to the Roman Catholic Church, educating candidates for deacon and priest ordinations in that Church. Not all theology students will end up working in or for a Christian Church, whether ordained or not – on the contrary – but the possibility itself requires extra safeguards.

The Tilburg School of Catholic Theology has been recognized by both the Dutch (and European) government and by the Holy See (the official name of the Vatican), enabling it to provide academic degrees for both a secular and an ecclesial context (see also under the previous Chapter 2). In concrete, this means that the Catholic Church – by way of a specially appointed Great Chancellor (usually but not necessarily the Archbishop of Utrecht) – has some influence on the various theological curricula in the Faculty, in terms of the program, as well as in terms of providing an ecclesial missio canonica (Latin: ‘canonical mission’) to all lecturers involved in the curricula that are followed by candidates for ordination in the Catholic Church.

This missio can come in two forms: either a venia docendi (‘permission to teach’) or a nihili obstat (‘nothing stands in the way’). The second is required for lecturers in core courses of theology (systematic theology or moral theology for example), while the first is needed for other disciplines. A venia docendi is granted by the Great Chancellor and the nihil obstat by the Vatican through the Great Chancellor, both based on an assessment of the (candidate) lecturer’s adherence to and involvement in the Catholic faith. Through this system the Catholic Church can exert theoretical and practical influence over the corps of lecturers.

This double system has the advantage of a dual recognition of the academic degrees given by the faculty – secular and ecclesial – but it also requires a balancing act from both the university/faculty and the Holy See/Great Chancellor to ensure academic freedom on the one hand and a recognizable ‘Catholic’ identity on the other.

4. Academic hygiene

One of the most important things in university life is academic hygiene.

Forms of academic fraud

There are many kinds of conduct regarded as academic fraud, even when no wrongful intent is involved. The following list contains the most important forms of academic fraud, but the list is not exclusive. As a rule of thumb, if you would be ashamed to tell your grandmother about it, you should probably not do it.

Plagiarism. Presenting someone else’s work, ideas, or words as your own without acknowledging this as such.

Duplicate submission (sometimes called ‘self-plagiarism’). Reusing one’s own previously submitted or published work without disclosure.

Fabrication. Making up data, sources, or results.

Falsification. Manipulating data, methods, or results to misrepresent the research outcome.

Ghost writing (or Contract cheating). Submitting work written by another person (paid or unpaid) as your own.

Improper collaboration (or unauthorized assistance). Receiving help in a manner not permitted by the assignment or institution.

Misrepresentation of credentials or contributions. Falsely claiming qualifications, authorship, or research involvement.

Citation manipulation. Distorting or inflating citation practices with intent to mislead regarding the scholarly significance of a work.

Sabotage. Intentionally hindering or damaging the academic work of others.

Ethical misconduct. Violating ethical standards in studies involving human or animal subjects.

Citing: referencing and style sheets

Among students, the most common form of academic fraud is (unintended) plagiarism. Usually this happens because the student does not know how to refer to other (scholarly) works and how to properly quote them. If you want to build on previous work by other authors, you have three possibilities to denote this as such:

Quoting: a verbatim (word-for-word) rendering of someone’s work. Use quotations marks (like ‘ and ’ or “ and ”) and clearly present the source, including the page number(s).

Paraphrasing: a rephrased and usually abbreviated or summarized version of someone’s work in your own words. No quotations marks are needed, but clearly present the source, including the page number(s).

Alluding: a mentioning of someone’s work without going into details. No quotation marks are needed, but clearly present the source.

Whether you quote, paraphrase, or allude to someone else’s work, you need to provide the full bibliographical information to your reader. How you do that depends on the style sheet that is given to you by your lecturer, faculty (for students), editor, or publisher (for post-masters). Unfortunately, there is a vast number of style sheets out there in the wild, all differing in various major and/or minor details. So, you will have to check every time carefully. The most important distinction is whether the style sheet in question uses an ‘author-date’ or ‘footnote’ system.

The author-date system uses the surname of the author, the year of the publication and the number of page(s) between brackets within the actual text. At the end of the chapter/article/thesis/book, an alphabetical list of publications is provided, called a ‘bibliography’. This is common in empirical sciences. Example: APA style sheet.

The footnote system provides all bibliographical information at the bottom of every page (usually in a distinct, smaller font). Sometimes the information is placed at the end of every chapter or at the end of the whole book, so-called ‘end notes’. The number of the footnote corresponds with a superscripted one in the actual text above. Please, use automated footnoting in Word or other text processing software! This is common in the humanities. Example: Chicago style sheet.

There is a third, hybrid system: it uses footnotes, but in abbreviated forms and a full bibliography at the end of the chapter/article/thesis/book.

Let us return to the differences between quoting, paraphrasing, or alluding to someone else’s work in your own text with the help of an example, a specific part of my article: ‘The Art of Playing God. On Theology and Video Games. The Case of Metro Last Light,’ Journal of Systematic Theology 3/5 (2024), 1-52. This specific quotation comes from pages 3 and 4:

A video game is a “text”, that is, it communicates (however troublesomely and imperfectly) a message (however inconceivable, objectionable or cryptic in nature) from a sender to a receiver. And because it communicates, it can be interpreted as such. In the case of video games, we have one or more developers sending a message through their video game to one or (hopefully) far more players of that same game.

If you want to allude to this, you have to provide the complete source as indicated above either in a footnote or in author-date form + bibliography format. Here in author-date format:

…as Bosman (2024:2-3) argues that games are texts too….

If you want to paraphrase this, you have to rephrase and summarize the original passage in your own words, and you have to provide the complete source as indicated above either in a footnote or in author-date form + bibliography format. Again, in author-date format:

A video game can be regarded as a ‘text’, that is, a medium through which a message is conveyed from a sender to a receiver. Because it engages in communication, it invites interpretation (Bosman 2024:2-3).

If you want to quote this, you have to use quotation marks and you have to provide the complete source as indicated above either in a footnote or in author-date form + bibliography format. Again, in author-date form:

…one could argue that ‘a video game can be regarded as a “text”, that is, a medium through which a message is conveyed’ (Bosman 2024:2-3)…

These are the basics. Always check the specific style sheet provided.

Artificial Intelligence, academia, and theology

Artificial intelligence software has been available to us since Jospeh Weizenbaum programmed ELIZA to mimic a Rogerian psychotherapist. In 1997, Deep Blue won from world champion Garry Kasparov. For many lay people, this was their first experience with the phenomenon. From 2011 to 2014, Apple’s Siri, Google Assistant, and Amazon’s Alexa brought AI to the masses. However, when ChatGPT was publicly released on November 30, 2022, something momentous changed. Suddenly, artificial intelligence was no longer confined to narrow tasks such as playing chess, retrieving information, or processing voice commands. With ChatGPT, the public encountered a form of AI capable of generating coherent, context-sensitive, and often impressively human-like text. The momentousness of ChatGPT’s release lies not only in its capabilities but also in its accessibility: ChatGPT presented itself as an intuitive, conversational interface, available to anyone with an internet connection. The result was a rapid and wide-scale integration of generative AI into education, journalism, business, and the arts.

However, advanced AI systems like ChatGPT present a range of significant challenges or even dangers. First, these models can generate convincing but factually incorrect information (called ‘hallucinating’), leading to misinformation. They also inherit and amplify societal biases embedded in their training data, risking various forms of discrimination. Privacy concerns arise because training data often includes sensitive personal information, which models might inadvertently expose. Moreover, AI can be exploited maliciously for propaganda, deepfakes, and social manipulation, threatening democratic processes. Importantly, training and using large models demands enormous energy, contributing to environmental degradation and carbon emissions. Lastly, these models are often trained on massive datasets scraped together without explicit consent from creators, raising legal and ethical issues surrounding intellectual property and fair use.

In 2025, the Dicastery for the Doctrine of the Faith and the Dicastery for Culture and Education (two departments of the Vatican) published a joined nota, called Antiqua et nova, on the ‘relationship between artificial intelligence and human intelligence’. Among other things, it argues that artificial intelligence should not be seen as an artificial form of human intelligence but as a product of it. The Vatican also warns that AI runs the risk of aggravating discrimination, poverty, and social inequalities, by creating and maintaining the digital divide between rich and poor.

For academia, AIs like ChatGPT provide domain-specific problems, on top of all the aforementioned issues. Excessive and/or uncritical use of AI systems can seriously undermine the students’ learning processes, such as reading, summarizing, critical evaluation, analytical reasoning, and writing. This devaluates the worth of BA and MA diplomas, diminishing the possibilities of former students to make a real difference in the world around them. However ‘intelligent’ AI may seem, it is only capable of reformulating and connecting things that have been fed into the system. This means that AIs remain within the established paradigm, without the possibility of creating paradigm shifts (like the Copernican Revolution or the Digital Revolution itself), which have been crucial to the greater development of humankind.

Secondly, professors and examinators are trying to find specific kinds of assignments that are resistant to AI-generated responses. Oral or written exams (in a controlled environment on campus) are a possibility, but these forms cannot always be implemented for all the forms of competences a university bestows upon its students. Thirdly, AIs may increase inequality among students and universities. Institutions or individuals with greater access to advanced AI tools may gain unfair advantages in research productivity or publication, widening existing disparities between wealthy and resource-poor settings.

It is impossible at this time to present any definite rules on how you – as a student – may or may not use AI in your academic work. This is an ongoing debate right now. What is clear at the present, is my very strong recommendation that you should always disclose if and how you have used AI systems for your work (as I have done at the beginning of this book). And lastly, stay vigilant when working with AI, like you would be with all sources and/or tools at your academic disposal.