For the atheists: Here is an excerpt from a Christian tract or leaflet I have from years ago. The writer is describing handing out leaflets on a streetcorner and encountering an atheist.:
"Save it " she said. "I'm an atheist. "
"Really?", I asked. "Swear to God", she replied, and we both laughed.
"May I ask you a question then," I said. "Sure, go ahead."
"Can you give me any hard, cold evidence for the non-existence of God?"
"Yeah," she said, thinking. "I'm a realist. I believe in what's sensible and mature. I believe in facts."
"No good," I replied. "Hard, cold evidence, remember/"
" OK. I don't believe in what I can't see. Since I can't see God, then He doesn't exist."
"So tell me, do you believe in wind?"
"I believe in wind," she parried, "because I can see what it does. I can see the evidence of it all around me."
I looked up at the sky and the stars. "Funny, that's one of the reasons I believe in God."
Did I prove to her that God exists? No, but then I didn't have to. It isn't encumbent on any of us (Christians) to prove that God exists. We need only demonstrate that He may exist; that there's no intelligent basis for believing categorically that He doesn't exist; that believing in God is no less reasonable than a patent denial. In fact, believing is more reasonable, for when it comes to mustering up evidence, "The heavens declare the glory of God, and the firmament shows His handiwork." (Psalm 19:1)
...And if we hold God accountable for what he does or allows to occur in our lives, then He must be holding us accountable for our actions or omissions as well. Uh-oh, that's no fun! Who wants to be accountable to a being who's not only bigger and stronger, but who knows better? How can we do what we want if there's a God who is telling us to walk in His ways? Rather than accept accountability, then, we say "There is no God."