Big gods came after the rise of civilisations, not before, finds study using huge historical database

Sapiens is a good read that has some further ideas about the rise and fall of particular types of gods.

This reminds me a ton of Julian Jaynes' bicameral mind theory - he argues that consciousness is a recent development, and that until a few thousand years ago, the mind was split into a half that spoke (in the form of muses, voices, etc), and a half that acted on those commands.

Then the collapse of bronze age civilizations led to complex scenarios that required self-aware capabilities (for instance, to detect or issue lies), causing a push towards integrated consciousness. Religion is then a side-effect of this collapse, as the new conscious person.

The methodology is pretty similar too - comparing different texts in history's references to introspective concepts, understanding of the gods, etc.