Originally posted by Malacasta
What is the belief system for an atheist?
You believe that God doesn't exist, you believe that the earth was formed as a product of some cosmic explosion 'X' billion years ago, you believe that you have a monkey in your ancestry, etcetera. These are all points of faith; there is no scientific proof for any of them (and actual scientists who genuinely believe in evolution recognize it as a belief - it's only laymen who think it's fact). You probably have some sort of belief about what happens after death, too - whatever it may be. These beliefs affect your thinking - especially your belief about death. If you believe that death is the end of you, then you're living for the here and now, or at best to get a decent mention in history books. If you believe in reincarnation, you'll act such that you'll get reincarnated well. Etcetera.

Note, I use "you" here but am not speaking about any particular person.