About C.S

(CNN) - He looked like a “red-faced pork butcher in shabby tweeds, ” lived secretly with a woman for years and was so turned on by S&M that he once asked people at a party whether he could spank them.

We’re talking, of course, about C.S. Lewis, the Christian icon and author of classics such as “Mere Christianity” and “The Chronicles of Narnia.”

It’s tempting to remember Lewis only as the self-assured defender of Christianity who never met an argument he couldn't demolish. His death 50 years ago, on November 22, 1963, was overshadowed by the assassination of President John F. Kennedy. He has since become a patron saint of American evangelicals.

But the actual man whom friends called “Jack” had a “horrible” personal life, thought he had failed as a defender of Christianity and spent so much time in pubs that his publishers initially struggled selling him to a religious audience, scholars say.

“American publishers worried about offending their more puritanical readers because it seemed impossible to get a dust jacket picture of Jack without a pint or a cigarette, ” says Michael Tomko, a literature professor at Villanova University in Pennsylvania.

There are three other parts of Lewis’ life that clash with his image as well:

1. His religious books made him poor

No modern Christian author sells like Lewis. The cumulative sales of his Christian books for adults - not including the Christian allegory and children's fantasy "The Chronicles of Narnia" - now approach 10 million copies, according to HarperOne publishers. “Mere Christianity” sold more than 150, 000 copies over the past year alone. Perhaps the only publishing parallel to Lewis' works would be “The Lord of the Rings” trilogy, a mythology written by Lewis’ close friend and fellow Christian J.R.R. Tolkien.

But Lewis never got rich from his Christian classics, says Michael Maudlin, executive editor at HarperOne.

“His books left him poor, ” Maudlin said. “He had all of this money coming in, but he didn’t take those royalties.”

Lewis vowed to donate all the money he made from his books on Christianity, Maudlin says. He got big tax bills for his Christian books but struggled to pay them because he had given the money away.

Lewis refused to renounce his vow even though his money worries persisted throughout his life, Maudlin says.

“He is a man whose number one anxiety in life was poverty, ” Maudlin said. “Because his dad overspent, money was always a worry. He didn’t fix things in his home because he and his brother worried about poverty.”

Lewis’ financial worries stalked him until the end, says Alister McGrath, author of the acclaimed new book “C.S. Lewis: A Life.”

Lewis’ health began to fail near the end of his life, so he wanted to hire a private secretary to help tend to his affairs. His income, though, was so spotty that he told his potential secretary that he didn’t know whether he could pay him, McGrath writes.

Lewis was more worried about losing his teaching salary from the University of Cambridge than his book royalties, says McGrath, a professor at King's College London.

“Lewis was convinced that his books would cease to be popular and thus generate little in the way of income, ” McGrath said.

2. He felt like a failure as a Christian communicator

"Brilliant" is one of the most common words used to describe Lewis. He seemed to have read everything, and he could easily write in several genres: children’s fantasy, science fiction, Christian apologetics and autobiography.

“He had an almost photographic memory, ” Maudlin said. “He could recite the passage and page of a line from a book on medieval poetry.”

Lewis was not so adept in the ordinary world. He never learned to drive or type because he was too clumsy. And he was a shabby dresser who lived in a house that was falling apart.

He even began to doubt his ability to defend Christianity.

Lewis' breakthrough came as a Christian apologist, one who publicly defends and explains Christianity by invoking logic. He delivered a series of talks on Christianity for BBC radio during World War II that made him famous (you can hear some of those talks on YouTube). His fame crossed the Atlantic in 1947 when he made the cover of Time magazine.

But just as his fame peaked in the 1940s, Lewis began to doubt his persuasive powers, McGrath says.

Debating Christianity in public became “draining” for Lewis, McGrath says. At a 1945 lecture on Christian apologetics, according to McGrath, Lewis said, “Nothing is more dangerous to one’s own faith than the work of an apologist. No doctrine of that faith seems to me so spectral, so unreal as one that I have just successfully defended in a public debate.”

Lewis then lost a highly publicized debate to Elizabeth Anscombe, a young Catholic philosopher who pointed out inconsistencies in his reasoning. They clashed over passages in his book “Miracles, ” which he later revised. Lewis’ confidence was shaken further when he realized that his argumentative powers had little effect on some of his closest friends and relatives, who remained hostile to Christianity, McGrath says.

Lewis thought that he had “failed as an apologist towards those who were closest to him, ” McGrath writes. “How could Lewis maintain a profile as a public apologist with any integrity in the light of such private failures?”

When the BBC asked Lewis to participate in a discussion on the evidence of religious faith, he declined: “Like the old fangless snake in 'The Jungle Book, ' I’ve largely lost my dialectical power.”

Some contend that even Lewis’ faith failed him.

He lost love not long after finding it late in his life: Joy Davidman was an American writer who befriended Lewis by letter and eventually became his wife. She died of cancer at 45 with Lewis at her bedside. Their love affair was depicted in the 1993 film “Shadowlands.”