How did religion develop? A series that reads the evidence through many lenses

How did religion begin, and how did it change into the religions people practise today? This series follows the development of religion from the cognitive science of belief and the first burials, through Göbekli Tepe, the first states and the Axial Age, to the origins of monotheism, early Christianity, the East–West Schism and the 2020s data on whether religion is declining.

Each stage of that history can be looked at in more than one way. An archaeologist sees pits, pigments and pillars. A cognitive scientist sees minds that detect agents and look for purpose. A historical critic sees texts with authors, dates and agendas. A sociologist sees institutions, cohorts and survey curves. A Catholic or Orthodox theologian sees a creature made for God, seeking him "among shadows and images", in the Catechism's phrase. These are not always rival answers to one question. Often they answer different questions about the same evidence.

So every post in this series looks at one stage through several labelled lenses, and says honestly where each lens fits the evidence and where it strains. The series takes the theological lenses as seriously as the scientific ones. That does not mean treating them as interchangeable. It means stating each one in the form its best defenders would recognise, and then testing it against what the record actually shows.

The parts

1. Why are humans religious? What the cognitive science of religion found, and what failed to replicate. Agency detection, "born believers", religious priming, and why cultural learning now explains more than cognitive biases do.
2. The first signs of religion: burials, cave art and Göbekli Tepe. From the first deliberate burials about 100,000 years ago to the Neolithic monuments of Anatolia, and how far material remains can tell us about belief.
3. Gods of the first states: temples, divine kings and human sacrifice. Mesopotamia, Egypt, the Shang, the Indus, Vedic India and the Americas.
4. The Axial Age and the one God: how monotheism emerged in ancient Israel. Jaspers' thesis and its quantitative test, and Israel from Canaanite El to Second Isaiah.
5. Did "Big Gods" build civilisation? The moralizing gods debate and the retracted Nature paper. Field games, phylogenies, the Seshat dispute and what is left of the hypothesis.
6. From Jesus to the Schism: what historians can establish about early Christianity. The historical Jesus, early worship of Christ, the growth of the Church, and Catholic and Orthodox readings of how doctrine develops (Newman and Florovsky).
7. Where did religion come from? Classic theories and the Church's own frameworks, tested against the evidence. Tylor, Frazer, Durkheim, Freud, Lang and Schmidt's primordial monotheism, Girard, Eliade, Justin Martyr's seeds of the Word, Nostra Aetate and the Catechism.
8. Is religion dying? Secularization theory against the 2020s data. Pew's 2025 global figures, the Catholic Church's statistics, Orthodoxy, and the problems with the UK's "Quiet Revival" survey.

The parts can be read in any order. Part 7, on theories of origin, works as a second introduction for readers who want the big frameworks before the evidence.

The lenses

The same labels appear in every post:

• Cognitive and evolutionary science: how human minds acquire, remember and pass on religious ideas, and whether religion is a by-product of other mental capacities or an adaptation.
• Archaeology: what the material record shows (burials, images, buildings, bones) and the chain of inference from objects to beliefs.
• Historical criticism: dating and reading texts as human documents, with sources, redactions and contexts.
• Sociology and quantitative history: institutions, populations, surveys and cross-cultural databases.
• Catholic theology: the Church's magisterial documents (Vatican I, Vatican II, the Catechism) and Catholic thinkers, from Justin Martyr and Augustine to Newman.
• Orthodox theology: the Orthodox Church's own voices, such as Florovsky, Schmemann, Afanasiev and the 2016 Holy and Great Council, which often frame the same questions differently from Rome.

Not every lens appears in every post. Where a lens has little to say about a stage, the post says so rather than inventing something for it to say.

How citations and uncertainty are marked

The series draws on eight sets of research notes, one per stage, in the religion-origins research project. The notes record, for every claim, whether the source was opened and checked or cited from its standard bibliographic record. The posts keep that distinction:

• Citations are inline, by author and year, with a link where the notes give one. Each post ends with a list of its sources and a link to the notes file it draws on.
• "(bibliographic)" after a citation means the work is cited from its standard bibliographic record and was not opened while the notes were compiled. No precise figure or quotation in the series rests on a work marked this way. Its main argument is described in paraphrase only.
• Quotation marks are used only for wording the notes record from a source that was actually read. Everything else is paraphrase.
• Where the notes found a discrepancy (two sources disagree, or a secondary summary misstates a primary paper), the post follows the primary source and says so.
• Each post ends with two short lists: what we can say with confidence, and what remains open. A contested view is never presented as settled, on any side.

Three corrections from the notes come up often enough to state here:

• The Seshat "Big Gods" paper in Nature (2019) was retracted in 2021. Its authors' revised analysis is in Religion, Brain & Behavior 13(2), published online in 2022.
• Lightner, Bendixen and Purzycki (2023, Evolution and Human Behavior) argue that moralistic supernatural punishment is probably not associated with social complexity.
• The UK "Quiet Revival" survey was found in 2026 to contain fraudulent respondents. YouGov apologised and said it would rerun the survey.

What this series is not

It is not new data analysis. Every number comes from a published source that the notes cite. It is not an argument for or against any religion. The series' working assumption is that a causal account of how a belief arose does not settle whether the belief is true. Philosophers on both sides largely accept that, and Part 1 explains why. It also assumes that a theological claim made in the language of history has to meet history's evidence.

Produced with AI assistance (Claude) from the cited notes in the religion-origins project. Check each citation against its source before relying on it elsewhere; the notes say which sources were opened.