Joel Osteen’s disturbing inability to say that Mormonism is something other than Christian reflects a particular affliction from which our culture suffers. I’m not sure what to call it other than the cult of agreeableness, a widespread tendency to avoid disagreement, conflict, and contradiction whenever possible, a disposition to never draw hard lines for fear that we’ll upset or make ourselves unattractive by the action.

But Christians must be willing to upset and be unattractive. After all, we believe things that are upsetting and unattractive. When Jesus tells us to pick up our cross and follow, he’s bidding us to do something that many others will avoid because laying down one’s life is hardly appealing. Dying to our ego,...