Atheism is the belief that nothing made everything. How can nothing make everything? What can nothing do? Nothing. You don't have to see God to believe in him. Who built the house? A builder? Who painted the painting? A painter? So the house and the painting didn't make themselves? All an atheist has to do is to look at creation and use some common sense. The atheist can also ask God to show him if he exists or not. God will answer him. Just ask him to prove whether he exists, and wait for an answer. Just say something like, "God, I don't know whether you exist or not. If you do exist, please let me know for sure."
Atheism is not believe in any deities or god, many budist can be considered atheist because they not believe in any god. And when Atheism proclaim that nothing made everything? Don't know a single person that think that, we only said that we don't know, if you said it because the Big Bang theory you are wrong because it only say that all matter in the universe was compressed in a single point billions of years ago and then expanded, no such nonsense like nothing made everything,