That seems to imply those billions of people religious are not rational, down to earth.
Theism in itself is a simpler explanation for existence than atheism, and yet many rational people are atheists. Is it because they weighted all the possibilities or because they discarded the option a priori?
We are all way less rational than we would like to believe.
I would argue that theism is not just a simpler explanation but a more naive one.
We could also explain computers as magic and it would be simpler than explaining it with electricity and math.
No religions are based in any observable facts* and thus being naive explanations, indistinguishable from magic.
* More like they are based on deprecated observable facts, at first the sun and nature, later man and it's dramas.
Now we now the sun is just a big ball of gas and man is just a big brained mammal.
That being said religion is just one area of many and you could be very rational in lots of them but be religious for whatever reason.
Theism in itself is a simpler explanation for existence than atheism, and yet many rational people are atheists. Is it because they weighted all the possibilities or because they discarded the option a priori?
We are all way less rational than we would like to believe.