IIRC, he was observing the absurdity of four lower-class boys from Liverpool eliciting more hoopla than the Son of God.
He was young, and the young say many stupid things. I still say many stupid things, as far as that goes. Later in his life he seemed to understand more clearly, as many of us do. And I do think he was capable of introspection, and I will always love and relate to many of his songs, though almost none that he produced on his own.
Imagine, while pretty, extols the benefit of God not existing, which I do not in any way endorse. All that being said, I was quite saddened when he was shot, I was also saddened when George Harrison passed away.
Nobody in the rock and roll world understood melody like the Beatles. No rock and rollers could distill common themes quite like them. They were blessed by God, whether they believed in Him or not, Lennon and McCartney were geniuses.
By the way, do you think Paul McCartney wears a toupee?