Does God exist?

There are actually 3 parts to this question:

Can we prove that God does exist?
Is it possible that God exists?
Can we prove that God does not exist?

I read an interesting quote this weekend relating to whether the existence of evil proves that God does not exist. I don't have the book in front of me but it went something like this.

Person #1: I would like an opportunity to ask God why, when he has the power to do something about it, he allows injustice, famine, pestilence, etc. to exist in the world.

Person #2: I am afraid that God will ask me that same question.