You certainly ought to behave in a godly manner, because God will destroy everything, and because only those people who are righteous will live in the new heavens and on the new earth.

2 Peter 3:11-13

11 Because God will certainly destroy all these things like I just said, you certainly know how you should behave. [RHQ] You should behave ◄in a godly manner/in a manner that pleases God► 12 while you eagerly/expectantly wait for Christ to return on the day that God has chosen [MTY], and you should try to make that day come soon. Because of what God [PRS] will do on that day, the heavens will be destroyed. ◄The elements/The parts of which the universe consist► will melt and burn up. 13 Although all those events/things will happen, we rejoice because we are waiting for the new heavens and new earth that God has promised. The only people who will be in the new heavens and on this new earth will be people who are [PRS] righteous.