One Awesome Inch said:
There is no 'reason' for faith.
I think there probably is, but we just haven't discovered it. In my mind, it boils down to a "least resistance" pathway in the brain which can either be developed/activated or not. Unsure if it's a built in thing, like language, or a cultural thing, but it exists so uniformly in so many different parts of the globe, it's hard to think that a penchant for faith, if not religion, is a very common human condition.
In this particular scenario, then religion becomes either a force of good or bad. Good, if it leads a believer to a better life, or a mind better able to cope with the world around them; bad, if a religion preys on believers to its own political or social ends, to the detriment of believers. In either case, the religion provides the social construct for expression of faith.
This ingrained predilection for faith is not quite as strong as the ubiquity of language in humans, but maybe more on par with or even slightly more prevalent than those who develop addictive circuits in the brain.
Some beliefs people pick up to fill this brain circuitry work to their benefit, others, not so much. What works for someone, may not work for someone else, which would explain the differences in religions belief and faith.
Ultimately, though, and regardless of modern trappings, I have to think that faith, belief, and religion, and the neural pathway which appears to be ready to accept such in humans, began as some racial survival trait, as most things do.
