I don't believe there is or isn't, "believing" one way or the other is a waste of effort and illogical.
I was born like that, but eventually someone brought the concept of a God up, so I had to address it like I would any other proposition I got presented with. I suppose I still don't "believe" either way, but I do have an opinion on the subject. Except for things I don't know about yet, I have an opinion one way or the other on any given subject. If you bring up something I'll take whatever small or large amount of information I have on it and I'll come to at least a very tentative leaning in some direction. That doesn't mean that I am forever married to that opinion, and it may be such a weak opinion as to be almost indistinguishable from being truly agnostic about the subject, but I will pretty much never fall dead center between two opposing ideas. I find it hard to believe that anyone does.
I think if you took someone who had never heard of God and asked them if they believed in Him, they should still be able render an opinion on the spot. I wouldn't necessarily expect them to defend that opinion in any deeply involved way, but they should still be able to say "Now that you mention it, I guess I could believe that", or "Nah, prolly not". Neither of those responses are exactly indicative of strong conviction, but they still fall on one side of the scale or the other. Insisting that I lie on the exact center of those beliefs takes more effort than either of those responses for me. It allows me to sit in judgement of both opposing sides, but it also requires me to make strawmen of both of them to ensure that I don't fall on one side or the other. I would have to believe that both sides are completely composed of people who are steadfast and unshakeable in their absolute belief that God either exists or doesn't. I'd have to deny the obvious fact that there are weaker versions of both that allow for the possibility of their opinion being incorrect even while making a definite statement about what they think is probably the truth of the matter. While I may clearly not be a member of the absolute belief groups, there is nothing in my personal philosophy that excludes me from the weak theist or weak atheist group. All I have to do is ask myself "What do I think is the truth, however tentatively"? I think that there probably isn't a God, so I'm an atheist.