I will be completely honest here, and then sit back and count the down-votes:
I do not believe there is a single member of this forum who does not believe, somewhere in a part of their heart and soul, that God exists. Including you.
I don't take offense to that statement. I even think I understand where it comes from. I had lost my faith in god many years before I acknowledged it. Not only did I never wish to stop believing, I pretended to believe even after I no longer did. By the time I admitted that I was a non-believer, there wasn't a shred of belief left to grasp.
I think that religious belief is emotional in nature. We approach god emotionally, and then we make a token attempt at making him fit our world rationally. Once we put emotion into its proper place and approach god and religion rationally, belief shrivels away. "Heart and soul" are just another way to say "emotional center." Anyone whose been head-over-heels in love knows that emotions are often irrational, and sometimes spectacularly so. And what generates a more emotional reaction than the belief in an almighty god who has a plan for us, who gives us a truly transcendent goal to aim for?