I think it is fair to say that most of the references in Scripture to Jerusalem are about Jerusalem of this present earth. That is to say,

“Jerusalem that exists now,” Gal 4:25 WEB

But when you read prophecy you must ask,
“Of which Jerusalem does
the prophet speak?”

Some are obvious, while others are not as clear.

It is true that there are some incredible things yet to happen with Jerusalem that now exists. Zechariah prophesied during the first return from exile (around 520 BC, Zech 1:1), in the time of Ezra and Nehemiah. Seemingly speaking of what Paul calls “Jerusalem that now exists,” Zechariah sees a day when,

““… ‘Thus says Yahweh of Hosts: “My cities will again overflow with prosperity, and Yahweh will again comfort Zion, and will again choose Jerusalem.”’””
Zech 1:17 WEB

In context he seems to speak of present Jerusalem. He speaks of it as an abundantly prosperous city, Zech 2:4, and a city faithful to God,

“I will strengthen them in Yahweh;
And they will walk up and down in his name,” says Yahweh.”
Zech 10:12 WEB

That clearly has not happened YET! Zechariah clearly pictures ALL the families of Israel (Zech 12:14) being converted to “ to me whom they have pierced;” Zech 12:10 WEB, and in Zechariah 13. This is spoken in Scripture as bringing a world revolution of righteousness (something Mystery Babylon deeply dreads). Paul says of those times.

“Now if their fall is the riches of the world, and their loss the riches of the Gentiles; how much more their fullness? ”
Rom 11:12 WEB

So some incredible good things are yet to happen with present Jerusalem.

But Peter says this present universe will vanish.

“… the heavens will pass away with a great noise, and the elements will be dissolved with fervent heat, and the earth … will be burned up.”
2Pe 3:10

He goes on to say “we look for new heavens and a new earth in which dwells righteousness.” 2Pe 3:13 WEB.

So when it says in Isaiah 65,

“17 For, behold, I create new heavens and a new earth; and the former things shall not be remembered, nor come into mind. 18 But be you glad and rejoice forever in that which I create; for, behold, I create Jerusalem a rejoicing, and her people a joy.”
Isa 65:17-18 WEB

… in context, the “Jerusalem” in Isa 65:17 is part of that “Jerusalem that is above” of Gal 4:26, and part of the new universe, the “new heavens and a new earth” of 2Pe 3:13.

The “never again”/ “no more” / “neither … any more,” and
all the “forever” sort of passages

are all about “Jerusalem” above, and what we call “heaven.”

So when the prophet David says of Jerusalem, “I will appoint a place for my people Israel, and will plant them, that they … be moved no more; neither shall the children of wickedness afflict them any more, as at the first,”
2Sam 7:10 WEB

The prophet really speaks of heaven here. Only heaven is “forever.”

WEB is the World English Bible, a copyright free revision
of the original ASV American Standard Version 1901