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Before you begin
What this site is, who it is for, and why it covers four traditions and not others.
You are reading the brief version. Switch the depth control to Complete for the full treatment.
This is a course in the fundamentals of the Christian faith, written for readers in four traditions: Catholic, Orthodox, Lutheran and Anglican. Choose your tradition at the top of any page and the material speaks from inside it.
These four are grouped together for a reason. Each one understands itself as continuous with the visible Church of the first thousand years. Each confesses the Nicene Creed as its own. Each baptises infants, believes baptism actually does something, and believes that what is received at the altar is more than a reminder. Each has bishops, an ordained ministry, and a settled form of public worship. They disagree with one another on real questions, and this site says so plainly rather than smoothing it over.
Material for Methodist, Reformed, Baptist, Pentecostal and non-denominational readers is not offered here. That is not a judgement on the sincerity of those Christians. It is a matter of scope: those traditions answer several of the questions in this course differently, and a course that tried to satisfy everyone would end up teaching nobody anything.
But you will meet those answers constantly. Every section contains a panel marked Where modern denominations differ, which names who disagrees, states their position at its strongest, and gives you the reply. The aim is that when a friend at work tells you infant baptism is unbiblical, you do not go quiet.
Two reading depths are available. Complete is the default and is what you should read if you want to know this properly. Brief gives you the same ground in a quarter of the words.
Reading alone will not do it. Every section asks you to stop, answer, argue and recall. All of that is stored in your own browser and nowhere else.
What this is
This is a self-paced course in what Christians have believed from the beginning: one God in three Persons, a world He made good, a race that fell, a Son who became one of us and died and rose, a Spirit who makes us His, a Church that carries His life, and an end that is not the grave.
It is written for an adult who was never taught this properly, or who was taught it once and has lost the thread. There is no assumed vocabulary. Where a technical word is unavoidable, it is defined in the sentence that uses it.
It is not devotional writing, and it is not apologetics dressed up as catechesis. It is an attempt to state what is true, why the Church has held it, where the traditions differ and where they do not, and how to say so out loud.
Why these four traditions
Catholic, Orthodox, Lutheran and Anglican. The grouping is not arbitrary, and it is not about how old a church is. It is about a cluster of convictions that these four hold together and that the traditions outside them do not:
- The Creeds are ours, not merely ancient. Nicaea is not a historical curiosity to be checked against Scripture; it is the Church's own confession, binding on her.
- The Church is visible. She has a structure, a ministry, and a continuity across time that can be pointed at, not merely an invisible fellowship of all true believers.
- Baptism does something. It is not a public declaration of a decision already made. God acts in it. Which is why infants are baptised.
- The Eucharist is not a reminder. What the faithful receive is Christ, in some real sense, however differently the four explain it.
- Worship has a given shape. Public prayer follows a form the Church has received, not one each congregation invents.
- The Church has a memory. What the Fathers, the councils and the liturgies handed down has authority, though the four disagree about how much and of what kind.
Pause and thinkBefore reading on - of those six convictions, which single one do you think divides these four traditions most sharply from Baptist and Pentecostal churches?
Most people say the Eucharist. In practice it is baptism, because it decides everything else. If baptism is something God does to you, then grace can come through material things and through the Church's ministry, an infant can receive it, and the sacramental logic of the other five follows. If baptism is something you do to declare a decision you have already made, then the Christian life begins with your choice, the Church becomes an association of the already-saved, and the other five convictions lose their footing one by one.
How the four are handled
The shared teaching is written once, as the main flow. Where a tradition says something the others do not, or says it differently enough to matter, it appears in a panel marked with the tradition's name.
If you have chosen a tradition, you see only your own panel. If you have chosen All four, you see them side by side, which is the honest way to read this site if you are trying to decide where you belong, or if you simply want to know what your neighbours believe.
The four are not treated as four flavours of the same thing. Where they genuinely disagree - on the papacy, on the filioque, on how many sacraments there are, on what happens to the bread - the disagreement is stated, not managed.
Catholic
Your panels draw on the Catechism of the Catholic Church, the ecumenical councils through the Second Vatican Council, and the Latin tradition's theologians, Augustine and Aquinas above all. Where the Catholic position has developed over time - on the sacraments, on the papacy, on salvation outside the visible Church - the development is described rather than flattened.
Orthodox
Your panels draw on the seven ecumenical councils, the Greek Fathers, the liturgies of Saint John Chrysostom and Saint Basil, and the later synods that responded to Western controversies. Orthodoxy has less appetite than the West for precise definition of how God acts, and that restraint is treated here as a position, not a gap. Where Orthodox practice varies between the Greek, Slavic and Antiochian churches, the variation is noted.
Lutheran
Your panels draw on the Book of Concord: the Augsburg Confession and its Apology, the Small and Large Catechisms, the Smalcald Articles and the Formula of Concord. Lutheranism is a confessional tradition, which means it has written down what it holds, and this site quotes those documents rather than guessing. Where Lutheran bodies differ among themselves, the difference is named.
Anglican
Your panels draw on the Book of Common Prayer, the Thirty-Nine Articles, the Ordinal, and the Caroline and Tractarian divines. Anglicanism is the hardest of the four to state briefly, because it holds together an Anglo-Catholic wing that is nearly Roman, an evangelical wing that is nearly Reformed, and a great deal in between. Rather than pretending to a consensus that does not exist, these panels tell you what the formularies say, and then where the parties actually stand.
Two depths
Complete is the default. It runs one to two thousand words per section, with the differences among the four spelled out and the objections answered. Read this one if you want the material to stay with you.
Brief covers the same ground in a quarter of the length. It is for a second pass, for a commute, or for the evening you have fifteen minutes rather than an hour. It leaves out the argument and keeps the conclusion.
Switch between them with the Depth control at the top of every page. You can change at any point, including halfway through a section.
Why you are asked to answer things
Reading is a passive act, and passive acts do not stick. You can read a clear explanation of the two natures of Christ, agree with all of it, close the tab, and be unable to say a word about it a week later. Nothing has been fixed in you, because nothing was ever required of you.
So every section stops you:
- Pause and think. A question dropped into the middle of the reading. Answer it in your head, then compare. The gap between what you thought and what is actually the case is where learning happens.
- Check yourself. Multiple choice, with an explanation attached to every option, right and wrong. A wrong answer here teaches you more than a right one.
- Objection drills. A challenge, stated the way a thoughtful opponent would actually put it. You type your answer before you are shown a model one. Type something. The half-formed answer you write is worth more than the polished one you read.
- Memory work. Creeds, commandments, definitions and a handful of references, on cards that come back at widening intervals. Cards you miss return sooner. The Review everything page gathers whatever is due across the whole site.
About your data
Everything you type, answer and mark is stored in your own browser, using the browser's built-in database. None of it is sent anywhere. There is no account, no login, no analytics on your answers, and no server that could be asked for them.
The consequence is that your progress belongs to one browser on one device. Open the site on your phone and you begin again. There is an Erase my progress link in the footer that clears everything at once.
Work with it
Check yourself
According to this site, what is the common thread that groups Catholic, Orthodox, Lutheran and Anglican together?
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Correct. That single conviction generates the rest: a visible Church, an ordained ministry, sacraments that convey rather than merely signify, and creeds that bind.
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None of the four says this. All four hold Scripture to be God's authoritative word; they differ over how it is rightly read and what else carries authority alongside it.
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Chronology is not the criterion. Lutheran and Anglican churches date from the sixteenth century, and Reformed churches are just as old but are not covered here.
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Only the Catholic tradition does. The papacy is one of the sharpest disagreements among the four.
Check yourself
Why does this site ask you to write an answer to an objection before showing you a model one?
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Yes. The effort of retrieval, including a failed attempt, is what fixes material in memory. A model answer read cold feels persuasive and vanishes by Thursday.
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Nothing you type leaves your browser. There is no server to review it.
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The model answers are the site's considered position. They are simply withheld until you have tried.
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No data about you is collected at all.
Objection drill
A course that lets you pick your denomination and then only shows you your own side is not education. It is confirmation bias with a nice typeface. Real learning means confronting the strongest case against what you already think.
A model answer
The objection would be devastating if the tradition selector filtered out disagreement. It does not. It filters out the parts of the explanation that belong to traditions other than yours, in the same way a Spanish grammar written for English speakers does not also explain Spanish to speakers of Mandarin.
Notice what is never filtered. The Where modern denominations differ panel appears in every section regardless of what you have selected, and its whole job is to state the opposing case at full strength before answering it. The objection drills exist to put you in front of the sharpest challenge anyone is likely to make. And the All four setting is one click away, which lets you read the Catholic, Orthodox, Lutheran and Anglican treatments of a contested question side by side - something most catechetical material never lets you do at all.
There is also a real argument for depth over breadth. A person who understands one tradition properly can have a serious conversation with someone from another. A person who has been given a shallow survey of six positions can only report that opinions differ. Knowing where you stand is the precondition of genuine engagement, not the enemy of it.
Memory work
Turn each card over, then say honestly whether you knew it. Cards you miss come back sooner.