It was in your title, "How an Atheist Religion..."

There is no such thing as an atheist religion. I'm an atheist. I have nothing to do with religion. Religion is the belief in supernatural beings or gods. Humans are just like the rest of the animal kingdom. We are born, live a short time and die. God has nothing to do with it. Satanists are not atheists. They believe in a supernatural being - Satan.