Before his death at 62, Christopher Hitchens, the uber-atheist and best-selling author of “God Is Not Great: How Religion Poisons Everything,” considered becoming a Christian.

That is the provocative claim of “The Faith of Christopher Hitchens: The Restless Soul of the World’s Most Notorious Atheist,” a controversial new book winning both applause and scorn while underscoring, again, the divide between believers and atheists that Hitchens’ own life and work often displayed.

The author is Larry Alex Taunton, an evangelical Christian who knew Hitchens for three years and, he says, had private, unrecorded conversations with him about Christianity.

Those 2010 conversations, shortly after Hitchens was diagnosed with the esophageal cancer that would kill him 18 months later, took a serious turn.

Once, he asked Taunton if his friend understood why he, Hitchens, did not believe in God.

“His tone was marked by a sincerity that wasn’t typical of the man,” Taunton writes. “Not on this subject anyway. A lifetime of rebellion against God had brought him to a moment where he was staring into the depths of eternity, teetering on the edge of belief.”

Taunton, 48, founder of Fixed Point Foundation, an organization that defends Christianity, acknowledges in the book there are “no reports of a deathbed conversion” for Hitchens.

But Taunton writes that during the same time period, “Christopher had doubts … and those doubts led him to seek out Christians and contemplate, among other things, religious conversion.”

“At the end of his life, Christopher’s searches had brought him willingly, if secretly, to the altar,” Taunton writes at the end of the book. “Precisely what he did there, no one knows.”

The book, published by Christian publishing house Thomas Nelson, is proving popular among evangelicals, winning praise from Douglas Wilson, another of Hitchens’ Christian friends and debate partners, and from Chris Matthews, a Catholic, who said during an interview with Taunton on his MSNBC show, “Hardball with Chris Matthews,” that the book is “beautifully written.”

But among members of Hitchens’ inner circle, the book’s claims that Hitchens was too famous an atheist to admit his late-in-life change of heart, that he was privately “entering forbidden territory, crossing enemy lines, exploring what he had ignored or misrepresented for so long,” are getting a decidedly different reception.

Steve Wasserman, who was Hitchens’ friend for 30 years, co-executor of his estate and with Hitchens’ family at his death, called the book’s claims “petty” and “appalling” when they were read to him.

“I am not in the position to dispute what Taunton says were private conversations,” he said by phone from New Haven, Conn., where he is executive editor-at-large for Yale University Press. “But I really think it is a shabby business. It reveals a lack of respect. This is not a way to debate Christopher Hitchens’ beliefs — to report unverifiable conversations, which amazingly contradict everything Christopher Hitchens ever said or stood for.”

Benjamin Schwarz, Hitchens’ editor at The Atlantic, where he published some of his best work, said, “That Christopher had friends who were evangelicals is testimony to his intellectual tolerance and largeness of heart, not to any covert religiosity.”

And Michael Shermer, an atheist and founder of Skeptic magazine, who read the book’s manuscript and liked its description of the friendship between the two men — enough to give it a favorable jacket blurb — said Taunton’s claims of Hitchens’ flirtation with conversion were “exaggerated.”

Reached by phone at his home in Birmingham, Ala., Taunton stood firm in the face of such criticism. Asked about the fairness of publishing such claims about Hitchens after his death, he said: “The things that I relate, I think by and large I substantiate. What I am saying is this: If Christopher Hitchens is a lock, the tumblers don’t line up with the atheist key and that upsets a lot of atheists. They want Christopher Hitchens to be defined by his atheism, and he wasn’t.”

Taunton first met Hitchens in 2008 in Edinburgh, Scotland, where both were involved in a debate about religion. Hitchens famously said he would debate anyone, and Taunton often arranged and moderated debates between Hitchens and noteworthy Christians.

The two men became friends and spoke warmly of each other in public — Hitchens once said in an interview, “If everyone in the United States had the same qualities of loyalty and care and concern for others that Larry Taunton has, we’d be living in a much better society than we do.”

Taunton writes of his deep concern for Hitchens — for both his soul and his physical well-being. The two took two cross-country road trips after Hitchens became ill, and Taunton’s recollections of those trips and the conversations they had — untaped and unwitnessed by anyone else — form the heart of the book.

“I would say to any would-be critics, read the book,” Taunton said. “You will see that this a gentle treatment of Christopher Hitchens, far more gentle than his (book-length) assaults on the Clintons or Mother Teresa. I’ve given him the benefit of the doubt.”

Hitchens tried to ensure that anyone claiming he turned to religion at the end of his life would be discredited. In 2010, he made a video with The Atlantic’s Jeffrey Goldberg in which he said, “In the event of anyone ever hearing or reading a rumor of such a thing, it would not have been made by me. … No one recognizable as myself would ever make such a ridiculous remark.”