Stephen was an up-and-coming comedian, and a prodigal. Raised in a Christian family, he struggled with doubt after his dad and two brothers died in a plane crash. By his early twenties, he’d lost his faith. He found it one night on the frigid streets of Chicago. A stranger gave him a pocket New Testament, and Stephen cracked open the pages. An index said those struggling with anxiety should read Matthew 6:27–34, from Jesus’s Sermon on the Mount.

Stephen turned there, and the words kindled a fire in his heart. He recalls, “I was absolutely, immediately lightened. I stood on the…