I think he was just telling people to Imagine a world that didn't suck lol.
Yes, why not?
Songs are made for us to take then and give them a personal meaning.
The word “imagine” is very hypnotic.
It allows a lot of leeway for the listener to dream up a personalised scene.
A hypnotist will get a client to “imagine” his/her happy place. This is usually a deserted island with a sandy beach and lots of palm trees.
I believe that Lennon’s Song is a more crowded version of the happy place idea. It’s basically a guided visualisation to help people feel better about their difficult lives.
Imagine + Pop song = Mass Hypnotherapy
The soothing melody is reminiscent of a lullaby.
I believe that Lennon used future pacing to try and persuade the listener to think positively about his ideas. He also used the principle of social proof:
“You may say that I’m a dreamer, but I’m not the only one.”
The word “imagine” is also used a lot in advertising. It’s a brilliant marketing strategy.