I voted for Tug Of War.
I think Imagine has elements that John did not really believe in. I know that John did not embrace a religion, and sometimes denied it. I still think he had some faith that there is a God, and possibly thought there is a religion he should have belonged to.
Tug Of War is multi-dimensional. It can be about the normal Tug Of War of life, or the Tug Of War in a relationship, or any other Tug Of War.