“Who are you to tell me that your morality is more right than mine?”

From this Commentary post by Peter Wehner, journalist and Christian Peter Hitchens gives his answer:

I would say the source of morality is not me. I’m merely informing you of another authority that seems to have a good deal more force than I could ever command. But in the end, of course, the illusion of self-authority—which has been one of the major developments of the past 100 years—has persuaded people that they need no such thing. And not only that they don’t need the concept of the deity, but that they actively want there not to be such a thing, which is one of the reasons the new atheism is such a passionate, intolerant and in many cases, rather unpleasant phenomenon. The people who have adopted it actively want there not to be a god. They know that if there is a god then that god must be a source of authority. If a purposeful creator made the universe in which we live, it would be idle to imagine that you could ignore that creator’s desires as to how you should live.

Wehner continues:

But as C.S. Lewis put it in Mere Christianity, while some of what we learn is mere convention (like whether we drive on the left or right side of the road), much of what we learn is (like mathematics) based on real truths. “If no set of moral ideas were truer or better than any other, there would be no sense in preferring civilized morality to savage morality,” Lewis wrote, “or Christian morality to Nazi morality.”