It was in March 1966 that Lennon made his infamous claim.
"Christianity will go," he told a reporter from the Evening Standard.
"It will vanish and shrink We're more popular than Jesus now - I don't know which will go first, rock and roll or Christianity. Jesus was alright, but his disciples were thick and ordinary. It's them twisting it that ruins it for me."
The boast provoked outrage, particularly in the United States, where conservative Christians burned piles of Beatles albums. The band received death threats and radio stations, particularly in the South, stopped playing Beatles records.
More than a decade later Lennon said he was glad of the furore he had caused. "My life with the Beatles had become a trap," he wrote in 1978.
"I always remember to thank Jesus for the end of my touring days; if I hadn't said that the Beatles were 'bigger than Jesus' and upset the very Christian Ku Klux Klan, well, Lord, I might still be up there with all the other performing fleas! God bless America. Thank you, Jesus."