(noun) A person who does not believe in deities.
"Atheism turns out to be too simple. If the whole universe has no meaning, we should never have found out that it has no meaning."
"I do not believe in God and I am not an atheist."
"A young man who wishes to remain a sound atheist cannot be too careful of his reading."
"I’m an atheist and I thank God for it."
"Atheists express their rage against God although in their view He does not exist."