I doubt any song is gonna save the world. And so what if we self destruct. Clearly if we get to that point, we deserve it. And the Earth is just fine. It'll be here long after we're gone.
Obviously though Imagine strikes a chord in people. That's all I'm talking about. The message may be a bit naive, but I think he knew that going in. He's clearly just making a point. And he DOES point out the fact that most of us probably can't imagine it. It's got a bit of pessimism in it if that's what it takes. And it's more than just lyrics. It's the tune, the voice, the delivery. It works. That's all.
And to compare it to Ebony and Ivory is just so wrong. Sorry. ??)