When Russell Moore, the editor-in-chief of Christianity Today, was interviewed recently on NPR, he told a chilling story about preaching. A number of pastors, he said, had reported to him essentially the same experience. They would be preaching on a passage like the Sermon on the Mount, including sayings such as “turn the other cheek,” “blessed are the merciful” or “love your enemies,” only to find themselves sharply attacked at...