This is difficult to answer because there is no established belief set, just like it is difficult to group non-astrologers or people unconvinced by Poseidon. Most non-theists have strong values and systems of ethics that guide their lives. This is driven by their conscience not dogma, scripture, or promises of the afterlife. The discussion of morality is a complex one and I touch on it later, but atheists think people can be good without God.