Of all that can transpire in a bedroom, nothing can be as titillating to the religious, or those of us who write about them, as a dying man’s conversion.

Oscar Wilde’s deathbed baptism remains a coup for the Roman Catholic Church 116 years later, and an embarrassment for those who cherish his legacy of hedonism. In his new biography of the poet Wallace Stevens, Paul Mariani repeats the claim that Mr. Stevens was baptized by a priest as he lay dying in a Hartford hospital.

There are others. Karen Edmisten, in her 2013 book “Deathbed Conversions: Finding Faith at the Finish Line,” recounts, with varying degrees of historical support, the putative deathbed conversions of Buffalo Bill Cody, John Wayne, the gangster Dutch Schultz and the mathematician John von Neumann.

The latest controversy about a late-in-life religious turn involves Christopher Hitchens, one of world’s most prominent atheists. In his new book, “The Faith of Christopher Hitchens: The Restless Soul of the World’s Most Notorious Atheist,” the evangelical writer Larry Alex Taunton writes about his friendship with Mr. Hitchens, the witty and impious author of “God Is Not Great: How Religion Poisons Everything,” who died of esophageal cancer in 2011. Mr. Taunton describes intimate talks that occurred during drives the two took together, which left him wondering if a dying Mr. Hitchens was edging toward belief in God. Unsurprisingly, evangelicals have celebrated the book, while some of Mr. Hitchens’s secular friends have winced.

Mr. Taunton runs the Fixed Point Foundation, which organizes debates between Christians and atheists. In September 2010, five months after Mr. Hitchens’s diagnosis of cancer, he and “Hitch” drove the 13 hours from Mr. Hitchens’s home in Washington, D.C., to a Fixed Point debate in Birmingham, Ala. The next month, after an event in Billings, Mont., they took a seven-hour trip to, and around, Yellowstone National Park.

As Mr. Taunton drove, Mr. Hitchens read aloud from the Gospel of John and mulled over the precise reason Jesus wept at the death of Lazarus. “Where is grace in the Old Testament?” Hitchens asked at one point, in Mr. Taunton’s telling. “I see it in the New Testament, but God is different in the Old Testament,” Mr. Hitchens observed, leading to a discussion of God’s covenant with Abraham.