Well, I was raised on it. If one day your Mom says, "don't touch the stove, it'll hurt", and voila she's right, you start to think maybe you ought to pay attention to what they're telling you some times, including when they talk about "God." Theres no way to distinguish one form of advice from the other until you get more experience. On this basis many things are acquired by making inferences based on the actions of people around us as we are growing up. "Everyone is wearing pants. Hmm. I guess I should too" is a pretty good heuristic Bayesian argument for many things, and keeps us out of trouble in unfamiliar experiences more often than not [cite some darwin page on here].

If I hadn't been raised that way, probably nothing would have promoted it to my attention.