Generally speaking, religion is probably inherent to human thought.
More than you might think. Interesting article in Newsweek last year on the emerging field of neurotheology: http://www.alchemind.org/neurotheo/neuronewswk.htm
Essentially, people having religious experiences (the feeling of being on a higher plane of existence, one with the universe, visions, talking to god, etc) show a marked decrease of activity in the area of the brain that connects the thinking mind with the real world. This has been found to be true across all varieties of religions and faiths. Now, does the religious experience cause this change in the brain, or does the change cause people to think they are having a religious experience? I don't know for sure, but I've got my theory.
Because the brain is ultimately how we perceive everything in the world, such an experience is every bit as real to the person having it as the keyboard is that I'm typing on. Thus one who has an experience like this is generally inclined to believe, with great conviction, that it was absolutely real. Hence, religion.
I doubt it. I'm a casual fan of the series; I appreciate the genre far more than the show.