We are not called to look longingly at heaven from earth;
we are called to look lovingly at earth from heaven.

2 Peter 3:11 says: "Since all these things are thus to be dissolved, what sort of people ought you to be in lives of holiness and godliness," This is an ethics question, it is not rhetorical; and it's based on an eschatological assertion. Peter isn't theorising about the end, he is basing current ethic on how the whole material universe will end! Our eschatology matters!
Paul answers Peter in Galatians 6:10: “So then, while we have opportunity, let us do good to all people…” We won't always have this opportunity, doing good will eventually be default, indistinguishable from doing anything, but now we have opportunity to shine in the darkness, to go against our animal instincts to grab, hoard, lie, steal, manipulate, and murder.