Here is a link that answers the usual questions theists ask about atheism: http://www.infidels.org/library/modern/mathew/intro.html
It responds to comments like:
"Isn't disbelieving in God the same thing as believing he does not exist?"
"Isn't it impossible to prove the nonexistence of something?"
"It seems to me that nothing will ever convince you that God exists"
"If atheism is not religious, surely it is anti-religious"
"Is atheism just a way to backlash against one's upbringing, a way of rebelling?"
"Aren't atheists less moral than religious people?"
"Don't atheists want to believe in God?"
"Of course atheists see no evidence for the existence of God - they are unwilling in their souls to see"
"Isn't life pointless to an atheist?"
"If atheism is so great why are there so many theists?"
"What about all the famous scientists who have concluded that god exists?"