Moral Relativism and the Diversity of Moral Opinion

Moral relativism looks like a coherent position that is halfway between moral absolutism and the rejection of all moral talk altogether. So people who are unwilling to derive their morality from a religion are faced with the quandary of how to go about using moral vocabulary in the face of that absence. I think they're very mystified by how there could be absolute facts about right and wrong, good and bad, in the absence of a supreme being.