Once, when he had behaved with particular rudeness to a young French intellectual at a dinner party in Paris at the home of Nancy Mitford, Miss Mitford, angry at his social brutality, asked him how he could behave so meanly and yet consider himself a believing and practicing Catholic.
"You have no idea," Waugh returned, "how much nastier I would be if I was not a Catholic. Without supernatural aid I would hardly be a human being."
-Bartlett's Book of Anecdotes (quoting a story about Evelyn Waugh related by Joseph Epstein)
[Something to remember when we see Christians not acting so Christlike is that perhaps they are still much, much better than they otherwise would be if they had not God's grace working in their lives so much.]