John Lennon's song is often disparaged like it’s some trite little ditty. I don’t think so. Its message is firmly existentialist: there is no heaven! We are being asked to imagine no heaven, no hell, no countries, no possessions. These are constructs, part of invented belief systems, often bizarre, often corrupt.
You don’t have to read into the lyric too much to get to the songwriter’s thoughts. He wasn’t making the case for a lion and lamb utopia as is sometimes supposed. He was too sardonic for that. He thought that if our constructs were imagined entities they could be re-imagined or simply abandoned. He also thought that humanity might come to live in harmony.
In short: adopt better beliefs and try to be peaceful. It’s not so hard to do.
Okay, maybe it is hard given the way people hold to their beliefs but it’s not unthinkable and it’s certainly not merely the cravings of a parvenu hippy. Imagine is as much rooted in the ex-Beatle's disillusionment as it is in his idealism, reflecting different aspects of a mercurial character: cynical, scathing, sensitive and creative. He was sceptical about the constructs and hopeful about the possibilities.
Burns wrote in similar vein two hunded years earlier: For a' that and a' that / It's coming yet for a' that / That Man to Man the world o'er / Shall brothers be for a' that. As an expression of optimism and promise it’s a fair enough statement for an artist to make though both men were also hard realists. In answer to criticism of his own lavish possessions Lennon gave the appropriate response: it’s only a song!
more than the cravings of a parvenu hippy