What are the functions of religion?

I believe the functions of religion are to keep people adhering to a standard code of ethics while worshiping with others with the same beliefs. Religion is commonly used to encourage good behavior and discourage what the faith believes to be sin. Since different religions believe different things, one answer to this question will never cover it all. To generalize - God is good, the devil is bad. Be good; go to Heaven. Be bad; go to Hell. Be atheist once you're dead there's nothing more. Hmmm, that's oddly similar to "Be good and Santa will bring you toys. Be bad and he will bring you coal. Stop believing and he will bring you nothing."