The Kingdom of God will be established on the earth and will replace all existing kingdoms. Initially there will be some opposition. Just look at this in Psalm 2:2:
“The kings of the earth set themselves, and the rulers take counsel together, against the LORD, and against his anointed,(Christ) saying, Let us break their bands asunder, and cast away their cords from us.”
But now look what happens in verse 8 where God will say to Jesus;
“Ask of me and I will give you the nations for your inheritance and the uttermost parts of the earth for your possession. You will break them with a rod of iron. You will dash them in pieces like a potter’s vessel.”
Jerusalem will be rebuilt and glorified and will become the capital of God’s kingdom which will eventually embrace all nations. Micah 4:2 says:
“Many nations shall come and say come let us go up to the mountain of the house of the God of Jacob and he will teach us of his ways and we will walk in his paths; for the law shall go forth from Zion and the word of the Lord from Jerusalem.”
There is a lovely picture of that future Jerusalem in Psalm 48:2;
“Beautiful for situation, the joy of the whole earth, is mount Zion, on the sides of the north, the city of the great King.”
Further reading:
Psalm 48:2. Isa. 24:23 Isa. 52:1.