In contrast to Pascal's Wager Triangle, Pascal's Triangle Wager argues that maybe God wants you to draw a triangle of numbers where each one is the sum of the two numbers above it, so you probably should, just in case.
Isaac Asimov's Bible guide convinced me that abrahamic religions are mostly made out from stuff either from Mesopotamia (Sabbath, Eden, the floods) or myths coming from later cults (e.g. Greece).
I don't know about the shrooms, my reading of the old testament made me think it started with some old guy trying to stop his nomadic desert tribe dying of anything too stupid by telling camp fire stories with some sort of message. The whole 'god will make the ground open up to swallow you and your family if you screw up' is a desperate attempt to scare them into not doing stupid things like slaughtering too many of their livestock at once, or eating shellfish whilst wandering around in a desert.
The stories get retold, changed and embellished over generations before being written down, and you end up with the weird mess of basic survival tips, animal husbandry, heroic stories and mystic fluff that is the OT.
The new testament is just the story of a fairly chill guy, with a slight messianic complex, wandering around with his mates and suggesting people be nice to each other, put through a similar transformation.
All Religion has its origin in shamanism. That then led to polytheism which then led to monotheism. What all those have in common is that people made it up as they went along.
Catholics also have patron saints for nearly everything from infants to ice skaters that they pray to but that are totally not gods because there is only one god. I mean, yeah, their second most important prayer is directed at the Virgin Mary, but that doesn't mean they worship her or anything.
Afaik, christians don't see the devil as a god, but as one of god's minions tasked with temping the flock or having them prove their faith or some shit.
This presumes some type of "pure" original religion — which indeed some people believe — as opposed to an evolving understanding that is relevant in each generation.
You seem to be confusing religion with a bible, which is probably a reflection of the dominant religion near you, but not every religion has a book, and not every religion with a book understands it in the same way.