I don't think that's so hard to understand. Our brains allow us to explore hypothetical scenarios in our heads. The difference between the imaginary and real is actually not that great. Our inability to tell the difference is exploited when we go to the movies. We're often pulled along a story and feel engaged even when we know it's all make-belief. And we've all wondered what happens in places we can't see. I see God as nothing but one of our faulty conclusions.
And why are Gods the way they are. It depends on tradition. In Abrahamic religion God is just a projection of an imaginary father or a perfect father we wished we had. In Pagan religion Gods are embodiments of the forces of nature. I have no problem seeing how these could gain traction. Anybody who has been in the vicinity of a lightning striking and who is already prepped with the Image of Zeus or Thor I'm sure would readily feel the guys presence. After all, we are emotional beings.
To me Gods are no mystery at all.
Right.
There was obviously a time in the human past when schizophrenia was more common, whether drug induced or not. There were less humans but there was much more of what we would categorize as a mental disorder among those humans. And for anyone who's ever witnessed the promiscuity and high energy levels and sudden onset of religious behavior that mark schizophrenic and bipolar behavior it isn't much of a leap to understand how these behaviors conferred survival advantages for both the individual and the species.
But even within that general schizophrenic behavior certain behaviors still get selected for and certain behaviors get selected against. Religion, where people sing songs to invisible space beings that they want to go live with and engage in obsessive compulsive behaviors is schizo lite. It's what's left. If your schizophrenia was such that you believed you could fly from the edge of a cliff you were selected against. But obsess about making a trek to your "holy place" or talk to a rock regularly and your behavior is selected for. So we have what we have today and we call it religion. Remember also that if you were a "rational" person in such a society your behavior would appear strange and might even get you killed, which history certainly shows it did.
But rational behavior still had a place in these schizo societies if you could build a better weapon or better war machine. What we have today is a lot more rational behavior, probably because there are more people crowded into less space.