You've got it backwards! That city is on earth during the 1000 years of Christ's reign with a rod of iron. Why would He need a rod of iron and why would "the nations" need healing if we/they are all in heaven??? Do you read the book of Revelation? It is the millennial reign of Christ ON earth and when that is over, He creates a new heaven and new earth wherein dwells righteousness. And I heard a loud voice from the throne saying: “Behold, the dwelling place of God is with man, and He will dwell with them. They will be His people, and God Himself will be with them as their God. ‘ He will wipe away every tear from their eyes,’ and there will be no more death or mourning or crying or pain, for the former things have passed away.” And the One seated on the throne said, “Behold, I make all things new.” (Rev. 21:3-5)
You’ve got it backwards!
Nope. I have it correct.
The righteous will live and reign with Jesus in heaven for the period of 1000 years, and judge the wicked. How do I know this happens in heaven and not on earth? Good question-
John 14:2 In my Father’s house are many mansions: if it were not so, I would have told you. I go to prepare a place for you.
John 14:3 And if I go and prepare a place for you, I will come again, and receive you unto myself; that where I am, there ye may be also.
At the second coming Jesus returns to earth to gather the righteous, that they may return with him to live in heaven in the mansions He has made for us.