Being an atheist is not passive, it requires an active stance

[emjay]

I think it could come down to two tendencies of the human mind: a) the tendency to try to understand anything that does not make sense, and b) the tendency to see agency in events (for instance ascribing human motives and feelings to insects). If that's the case then in pre-scientific times, when knowledge about the world was essentially non-existent, it would seem almost inevitable that the notion of human-thinking gods would come about. And in more modern times, when science explains most of the world, belief in gods could come down to ignorance of science (wilful or otherwise) or the fact that it still hasn't explained to everyone's satisfaction many of the deeper questions of existence and the universe.