2 Peter 3:10 says, “But the day of the Lord will come like a thief. The heavens will disappear with a roar; the elements will be destroyed by fire, and the earth and everything in it will be laid bare.” After the Millennium, the world as we know it will be disintegrated by fire.
Then, Revelation 21:1, 2 says, “I saw a new heaven and a new earth, for the first heaven and the first earth had passed away, and there was no longer any sea. I saw the Holy City, the new Jerusalem, coming down out of heaven from God, prepared as a bride beautifully dressed for her husband.” At that time, it truly will be finished! You can read Revelation 21 and 22 for a clearer picture of what that will be like.