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.

In his new book, “The Faith of Christopher Hitchens: The Restless Soul of the World’s Most Notorious Atheist,” the evangelical Christian writer Larry Alex Taunton describes a road trip he took in 2010 with the prominent atheist Christopher Hitchens, who was dying of esophageal cancer. The trip led Mr. Taunton to wonder if Mr. Hitchens was reconsidering his atheism. (Reprinted by permission of the author.)

May 13, 2016

Several Christian magazines have trumpeted Mr. Taunton’s work. In the Christian journal Books & Culture, Douglas Wilson wrote that “fewer things are sadder than the death of a defiant atheist,” yet Mr. Taunton’s “simply outstanding” book offers just enough hope for Hitchens’s salvation to make it useful for the church. “Ministers will be strengthened and evangelists encouraged,” he wrote.

Secular publications have been kind, too, with Publishers Weekly noting Mr. Taunton’s “smooth and accessible prose.”

But in an article by the Religion News Service last month, friends of Mr. Hitchens took exception with the book’s conclusions.

Steve Wasserman, a literary agent and editor, and an executor of Mr. Hitchens’s estate, described the book as “a shabby business” in which “unverifiable conversations” are made to “contradict everything Christopher Hitchens ever said or stood for.”

Having evangelical friends is a testament to Mr. Hitchens’s “intellectual tolerance and largeness of heart, not to any covert religiosity,” Benjamin Schwarz, his former editor at The Atlantic, was quoted as saying.

In an interview, Mr. Taunton said that his rather modest claims were being misunderstood.

“I wasn’t at his deathbed,” Mr. Taunton, 48, said. “I think on that first road trip Christopher was contemplating conversion. Do I think he had a conversion? No.” By the second road trip, he said, the moment seemed to have passed.

While The Christian Post declared that, according to the book, Mr. Hitchens “was contemplating conversion to evangelical Christianity,” Mr. Taunton said that was wrong: Even if Mr. Hitchens had come to some sort of belief, it is not clear what he would have believed in. Jesus Christ? An indescribable higher power? The Jews’ God (late in life, Mr. Hitchens learned his mother, and thus he, was Jewish)?

“Contemplating conversion and being close to Christ are two very different things,” Mr. Taunton said.

Still, Mr. Taunton laces his book with plenty of winks toward hopeful Christians, who would be understandably glad to see the conversion of an atheist as prominent as Mr. Hitchens. He quotes John le Carré’s George Smiley, who says, in “Tinker Tailor Soldier Spy” (the movie, not the book), “The fanatic is always concealing a secret doubt.” He writes that Mr. Hitchens had to keep up the front of an unquestioning atheist because itwas a matter of professional pride for him to play the part for which he had been hired.”

Mr. Wilson, who wrote the rave review in Books & Culture, is an evangelical pastor and a college professor. He has also written about private conversations with Mr. Hitchens about Christianity, and he said that Mr. Taunton’s experience of the man matches his own.

“I have been pastoring for decades,” Mr. Wilson said, “and in my judgment there was more of a personal interest” — in Christianity — “on Christopher’s part than the public stage persona would seem to indicate.”

Michael Shermer, who writes about atheism and science, initially gave the book a fulsome jacket blurb: “This book should be read by every atheist and theist passionate about the truth.” Since then, he has written on his blog that he would like the blurb removed.

Mr. Shermer said he had grown uncomfortable with how Mr. Taunton had, in interviews, used the metaphor of “keeping two books,” to refer to Mr. Hitchens’s bifurcated selves, one public and atheist, the other private and curious about religion. In the book, Mr. Taunton attributes the metaphor to Hitchens himself.

“In reality,” Mr. Shermer said, “there is no two books in a deceitful way.” But without that assertion about Mr. Hitchens, he “doesn’t have an interesting media story.” Mr. Shermer said it was just not believable that Hitchens was having doubts about his atheism, doubts shared with Mr. Taunton but almost nobody else.

“But you mean his wife, his family, his books, every interview he ever gave was all deceitful, but you, you got the real story?” he said, referring to Mr. Taunton. “I don’t think so.”

Mr. Taunton said he was planning to remove Mr. Shermer’s book blurb, but he questioned his motives.

“Could the man look any more silly to have written a glowing endorsement only to withdraw it when he took a bit of heat from his fans?” Mr. Taunton asked in an email.

Mr. Wilson agreed that, whatever the truth about Mr. Hitchens’s dying beliefs, the intrigue makes for a good story.

“Christians like the idea of saved in the nick of time,” he said. “They like the idea of a cliffhanger ending.”