I think we had god beliefs before we had intelligence; children go through a stage, when they realize that they are doing things, of thinking that anything that happens must have been done. Then they outgrow that particular fallacy (the jargon term in psychology for that stage). I would think that as human intelligence evolved it probably mirrored that (O recapitulating P and all that), so we would have god beliefs thrust upon us by our physiology before that physiology developed the brain we have now. Not a reason for god, but a reason for faith. And faith can be looked for in the brain - there are those cool epileptic nuns too.