How can yu be so sure that God does/doesn't exist?

Well, that is exactly what faith is...belief without seeing. I cannot say for sure if he exists, but without my faith in him my life would be hell. Yes, at times it is hard to believe, but deep down, I can just feel it in my soul, no matter how strong my doubts may be. Sometimes I think He is testing me, and it sure is hard, but like i said, deep in my soul I can just feel it. My heart always believes even when my mind does not.