this is a fashionable sentiment, but as Nietzsche (a man who cannot be accused of having much sympathy for Christianity) pointed out: The notion that a slave, humiliated and crucified, was as worthy of mercy and equal was nothing short of a complete overturning of the moral order of the world. Far from obvious it was radical and subversive. The kind of modern atheist who doesn't see this does so because he has Christian values so deeply in his bones he doesn't even realize it.