From reading your post, I can see how one without faith would see these books as collections of mythical stories from the past and fanciful and imaginary dreams about what is beyond death. I can see how you may perceive people of faith as being backward and lacking in intellectual capacity, but I assure you this is not the case. It is more of a matter of an intangible element, faith, that is present in some hearts and lacking in others.
My dad is a Christian theologian and works for the catholic church. I always had a great deal of interest in all things philosophy. When I was very young I had to go to church, later I was 4 years in a catholic private school (mostly just like any other school except for some mandatory ceremonies). I always refused to assume my dad is just an idiot fool and spent the better part of 15 years trying to get to the bottom of why do people take some stories so seriously and how does it make any sense.
My dad is definitely very religious and very well read. We got half a library of theological books and philosophical books at my parents house. My mom was always the counter weight as a secular humanist and a big fan of russian literature and all things politics. My fathers family is also very religious but traditional and theologically quite on a different level than my father.
For me one big interest has always been how one can people even start to have such strong faith in stories that seem so illogical. Why don't they expect more from a revelatory god than one book so indistinguishable form all similar books? The answers I found are quite complex. In short the basic concept of theistic absolutism doesn't work for me as in requires axioms I would yield and thus no abrahamic faith makes any sense.
For me one big problem has primarily always been the having faith in it part and actually believing it in the first place. Because I never did. Despite going to church until I was old enough to stay at home without a babysitter, I never actually believed any of it. I thought those grown ups are weird they must know something they aren't telling me.
You believed in Jesus before. That he is the son of god and simply revised it and apparently concluded that incorporating Mohammed makes more sense. The Mormons add their third book.
Indoctrination just didn't happen. I had two parents which I used to think where both religious when I was young, many religion teachers and just too much liberal influence. I was only indoctrinated into humanism if anything. (BTW humanism isn't atheistic but used to be a Christian thing for those that to make the wrong connections.)
I wouldn't say religious people are lacking in intellectual capacity. Some certainly do but so is it with many non-theists. Oftentimes I would argue there is a lack of intellectual honesty when one has faith in absolutist philosophies. I read some books and the proofs and thinking patterns of people that start out really smart end up with many short cuts the closer they get to proving what they are aiming at. At some point they throw all skepticism over board or simplify alternatives just to rule them out. Or like Hans Küng go by I like this more and 150 pages back I sort of proved that absolutist morals are necessary so these are the ones. Now they are absolut. :hiding:
Faith imo isn't good enough when one makes certain claims. Many people have faith in different opposing things. It is imo fine if religion stays a private non judging matter.
Some tribe in the desert some millenia ago is backwards by a simple civilization view point. I understand many Atheists are seen as arrogant and elitist because there is probably some truth to it (concerning those that actually express it and don't just keep it quite) but the "backwards" referred to the folks of that time and meant to imply that they had simpler problems, different problems and a different level of knowledge and development. It is a very arbitrary point in time and place to infuse a revelation and strange that an all powerful god cannot get more done than send 2-3 messenger in the same place and leave the rest of the world (if they even hear from them) to decide how much the hearsay that reaches them is to be trusted. Remember much of Christianities mission was never related to the bible. Most people couldn't read it all they got was preachers and missionaries until Luther came. Somehow it is the biggest religion in numbers today. Is it because of a trustworthy source of because of an appealing simple message? Or because of aggressive missionaries?