How to Build a Fictional Religion That Can Disagree With Itself

By Alexei Sassani

Most fictional religions in fiction fail in the same specific way: they’re handed to the reader complete. One founder, one revelation, one set of beliefs everyone in the world apparently agrees on. It reads like a Wikipedia summary of a religion rather than a religion — because real religions are never that settled, and readers can feel the difference even when they can’t name it.

The tell: nobody inside the religion disagrees with anything

Real religious traditions carry centuries of internal argument: disputed authorship, contested scripture, schisms, reform movements, and factions that read the same texts and reach incompatible conclusions. A fictional religion that skips all of that isn’t simplified, it’s unfinished — it’s a religion with the argument surgically removed.

When I built Ateshism for The Ashen Flame, the rule I kept coming back to was: every doctrine needs at least one group of believers who read it differently, and at least one open question the tradition’s own scholars haven’t settled. A few concrete techniques came out of that rule.

Give your scripture a genuine authorship problem

Ateshism has two sacred texts, written roughly three centuries apart. The first is attributed to the faith’s founder directly. The second surfaced centuries later, claiming to preserve teachings the founder held back until the community was ready to receive them — and whether that attribution is genuine remains an open, unresolved dispute within the faith itself, not a question the narrative quietly answers for the reader.

This does real narrative work beyond flavour. It means characters can hold the same faith and reach opposite conclusions about what it actually requires, without either side being straightforwardly wrong. It also means institutional power has something concrete to fight over: whoever controls how the disputed text is read controls a genuine amount of doctrinal authority.

Build institutions that can check each other

A single priesthood with total authority is a worldbuilding shortcut, and it shows. Ateshism’s clergy is split into two separate institutions with different jobs and, crucially, the power to investigate each other: one handles ordinary pastoral and civil matters, the other exists specifically to investigate misconduct, financial abuse and doctrinal heresy — including among the first group. That internal check is what makes the institution feel like it’s made of people rather than a single monolithic voice.

Let the tradition name its own unsolved problems

The single most useful thing I did for Ateshism was write a page that isn’t doctrine at all: a standing list of the faith’s genuine open debates — the problem of evil under a doctrine of universal divine presence, disputes over gendered religious authority, the reliability of religious experience as evidence. The tradition doesn’t resolve these for the reader. Its own scholars argue about them, the way real theologians do.

This matters because a religion that has already answered every hard question about itself doesn’t feel like a religion; it feels like a mission statement. Leaving real, load-bearing problems open — problems that would actually matter to someone living inside the belief system — is what lets readers trust that the world existed before the story started, and will keep being argued about after it ends.

The test I use

Before I count a piece of doctrine as finished, I ask: could two believers who both take this completely seriously reach different conclusions about what it means? If the honest answer is no, the doctrine isn’t done yet — it’s a rule, not a belief.

If you want to see how this plays out for one specific doctrine end to end — the argument, its strongest supporting case, and every objection I could construct against it, left genuinely unresolved rather than defeated — Divine Immanence is the fullest example on this site. And if the whole approach is what pulled you here, The Ashen Flame is the novel that grew out of building this world in the first place.