But the God hypothesis for morality and altruism has its own problems. It fails, for example, to specify exactly which moral judgments were instilled in people by God and which, if any, might rest on secular reason. It doesn't explain why slavery, torture, and disdain for women and strangers were considered proper behaviors not too long ago, but are now seen as immoral. For if anything is true, God-given morality should remain constant over time and space. In contrast, if morality reflects a malleable social veneer on an evolutionary base, it should change as society changes. And it has.
p. 177 - Faith vs. Fact (2015)