In Chapter 21, we enter a New Heaven and a New Earth which is too wonderful and too glorious to even describe (In our present limited state).
In Chapter 22, all is complete, all is fulfilled, Christ is reigning. However, there is a serious warning in verse 18: “I warn everyone who hears the words of the prophecy of this book; if anyone adds to them, God will add to that person the plagues described in this book. If anyone takes away from this prophecy, God will take away that person’s share in the tree of Life, and in the holy city, which are described in this book.”
“Then I saw a new heaven and a new earth; for the first heaven and the first earth had passed away, and the sea was no more.”
Revelation 21:1 NRSV