Belief in God is caused by various things based on the individual. There is no universal answer.What do you say??
Obviously, religion is not the first cause for belief in God. I would say rather that belief in God is the first cause of religion. But belief in God can be had through indoctrination, logic and reasoning, philosophical argumentation, reading of religious texts, and possibly many other reasons.
But there are as many reasons for one to lack belief in God, and I think it's an unrealistic expectation for atheists to "go to fundamentals" when the peripherals you mention are primarily the reason people support a belief in God. Just look around the forum at people who perpetually quote scripture and messengers.
With regard to the title question, yes, I believe in God, but not for the same reason(s) a theist does.