Frans (The Age of Empathy) de Waal uses this HuffPo piece to demolish the all-too-common "we'd be amoral without religion" argument. De Waal answers the inevitable Dostoyevskian complaints ("If there is no God, I am free to rape my neighbor!") this way:
Perhaps it is just me, but I'd be wary of anyone whose belief system is the only thing standing between them and repulsive behavior. Why not assume that our humanity, including the self-control needed for a livable society, is built into us? Does anyone truly believe that our ancestors lacked rules of right and wrong before they had religion? Did they never assist others in need, or complain about an unfair deal?
Drawing on findings from the field of evolutionary ethics, de Waal observes that "Human morality must be quite a bit older than religion and civilization. It may, in fact, be older than humanity itself:"
Other primates live in highly structured social groups in which rules and inhibitions apply and mutual aid is a daily occurrence. Acts of genuine kindness do occur in animals as they do in humans. The sequence of how various tendencies came into being is: first social instincts and empathy, then morality, and finally religion. This is of course quite the opposite from the origin story of Christian religion.
(That isn't the only thing that religion gets wrong, but that's an issue for another time...)