Few images of John Lennon are as iconic as that of the ex-Beatle playing a white piano in a white room, gazing into the camera lens while singing "Imagine." "Imagine there's no heaven. It's easy if you try. No hell below us, above us only sky. Imagine all the people, living for today," said Lennon, in the anthem that for many defined his life. "Imagine there's no countries. It isn't hard to do. Nothing to kill or die for, and no religion too."

Critics of the rock martyr have quoted these words almost as often as his admirers, especially in light of another quotation about religion that haunted the enigmatic superstar. In a 1966 interview about life in England, Lennon stated: "Christianity will go. It will vanish and shrink. I needn't argue with that. I'm right and I will be proved right. We're more popular than Jesus now."

Months later, his words were published in America. Many churches responded with bonfires of Beatles records and some Bible Belt radio stations banned the group's music -- for a while. Lennon received death threats.

Responding to the firestorm, Lennon told American reporters: "I pointed out that fact in reference to England, that we meant more to kids than Jesus did. ... I was just saying it as a fact and it's true more for England than here."

Decades later, pop-culture scholars and religious leaders continue to argue about what Lennon believed and when he believed it. This is the kind of topic that is being discussed in England, America and elsewhere during the fall of 2010 -- when Lennon would have been 70 years old.

Despite the images in "Imagine," Lennon "certainly wasn't an atheist, he was clear about that," noted Father Robert Hart, an Anglican traditionalist from Chapel Hill, N.C., whose "Hard to Imagine" essay was recently published in the journal Touchstone.

"What he was missing in his life was the certainty of a specific, definitive revelation of a particular religious truth. It's not that he denied that this kind of truth existed, but he was never able to find it. That's what he lacked and he knew it."

In other words, he was a vivid example of an attitude toward faith that has only gained power in the decades since his death. Lennon was "spiritual," but not "religious" before that stance became all too common.

And what about his statement that the Beatles were more popular than Jesus?

"The real problem with what John Lennon said in 1966 is not what so many were quick to assume and to decry in a knee-jerk reaction," noted Hart, in his essay. "The real problem is the element of truth in what he said. The Beatles WERE more popular than the Lord himself among youth in England at the time, as was Frank Sinatra among the older set in America -- and as are television, video games and many other things of this world to very many people today.

"Lennon, the eccentric artist, poet and musician, spoke all too accurately."

Lennon's life was defined by symbolic moments, noted Hart. He was -- literally -- born during an air raid and died after being gunned down by a mad man. As a teen, the vicar of the Liverpool parish in which Lennon was baptized and confirmed banned him from services for laughing at an inopportune time, almost certainly during a sermon.

As a global superstar, Lennon pushed his art and psyche to the limit while trying drugs, Eastern mysticism, psychics, astrologers and other ways of coping with life and his fear of death. As an adult he exchanged letters full of spiritual questions with televangelist Oral Roberts, at one point writing, "Explain to me what Christianity can do for me. Is it phony? Can He love me? I want out of hell."

For a brief time, Lennon tried to embrace evangelical Christianity. In the end, he called himself a "Zen Christian," among other labels.

One would have to conclude, Hart said, that Lennon both reflected his times and influenced them. He did his searching right out in the open.

"This was a man who, if anything, was almost too honest about his doubts and his beliefs," said Hart. "There are people who keep things bottled up inside. Well, that wasn't John Lennon. The question is whether anyone really listened to what he was trying to say."