Heres one for you:

If God is omnipontent (all powerful), omniscient (all knowing), and morally perfect, then how does evil exist? Wouldnt that contradict his characteristics? Sure we're given free will, but isnt it logically possible for good to create a human with less evil with the same free will? See, the problem with this is that it questions Gods goodness and power. Since we're supposed to live in his eyes, why are men so evil? Is it moral evil? Since we have free will, maybe evil is created by humans......

And the reason that its hard to believe/have faith in something we cant prove is a simple concept. We base our knowledge of perceptions that are confirmed with other perceptions on a daily basis. By looking at my chair, I know its a chair. Its a daily occurence. But you cant do that with religion simply because it cant be confirmed the way other things are.