Faith is trusting and believing in what we can't see. I know Jesus is right here because of the air I breathe, and the creation he made. I don't need to see him to know that he's real. Now, God's the judge here, not me, but I think that's one mistake that a lot of atheists make, they refuse to believe in him until they see physical proof. I love the verses in Hebrews about Faith, they're great.