When fire destroys it destroys.
”Then I saw a new heaven and a new earth, for the first heaven and earth had passed away, and the sea was no more…”
And a bit later: “And the One seated on the throne said, “Behold, I make all things new.”
This is in Revelation chapter 21. I can’t help you if you think this has already occurred.
”But each in his own turn: Christ the firstfruits; then at His coming, those who belong to Him.
Then the end will come, when He hands over the kingdom to God the Father after He has destroyed all dominion, authority, and power. For He must reign until He has put all His enemies under His feet. The last enemy to be destroyed is death. For “God has put everything under His feet.” Now when it says that everything has been put under Him, this clearly does not include the One who put everything under Him. And when all things have been subjected to Him, then the Son Himself will be made subject to Him who put all things under Him, so that God may be all in all.”
This is at His coming… when He returns.
I’m not the one claiming that God, when He is all in all in the age to come, in the new heaven and earth, is in the demons and evil people who are still burning.