It’s exam week and holidays are coming, so let’s play a game. We have a free copy of Bill Mattison’s Introducing Moral Theology for the reader who can give the best short account of what’s wrong with Andrew Sullivan’s “America’s New Religions.” I’ll summarize the argument and kick us off with some attempt to highlight a few of the major mistakes, and then I challenge readers to do better. A week from today, I’ll select a lucky winner of a free book.

There is a general sense of agreement, or at least a culturally enshrined assumption, that the...