Not "John Lennon is God" but rather two nouns separated by a comma. I refer more specifically to the song "God" by John Lennon.
This has always been one of my favorite Lennon solo songs. I do, sometimes, think that people believe in all of these "things" simply because they either don't want to or lack the ability to believe in themselves. Having faith is, in my estimation, wonderful; having faith in something else because you lack it in yourself is a terrible thought. None of us are disposable. Excluding mass murderers and dictators, none of us are so abhorrent and abnormal as to be so greatly deviated from the other. It's a lesson I've yet to fully master for myself by the way. I take solace though in the fact that John Lennon probably didn't either, as I take the song as being more about aspiration than actuality.