Heaven and Earth are eternal and everlasting because they do not live for or by themselves.
The perfect Sage puts his own interests last, and because of this unselfish way of being is always the leader of his people.
Because the Sage is looking after the welfare of his people, He preserves his own life essence.
Is it not because he is disinterested that his own interests are conserved?
One need only look to Catholicism to see that people must be dead to become Saints, gifted with the same kind of immortality on earth as that religion’s savior, such that people pray to them. Yet the changes they made in the world are still very real and visible and lasting.
What matters is the goodness that was done and that it was, in fact, done – not who did it, because the goodness lives on eternally.