how did you get this from that?
1 Corinthians 15:22 For as in Adam all die, even so in Christ shall all be made alive.23 But every man in his own order: Christ the firstfruits; afterward they that are Christ's at his coming.
The firstfruits shall have a place in Zion and so when Christ returns with the saints, New Jerusalem will come down from Heaven so that God will dwell among those saints coming out of the great tribulation and reign over the coming generations that has yet to know the Lord personally to believe in Him to be saved during the millennium reign of Christ.
Those saints coming out of the great tribulation will be serving the King of kings of Zion from all over the world in raising up the generations coming during the millennium reign of Christ for a thousand years, but I suspect they shall be marrying and having children to set a living example for those coming generation. Kind of like the requirement for being a bishop in 1 Timothy 3rd chapter. So they will set the example, but the difference between them saints coming out of the great tribulation and the coming generations is that the resurrected saints will not have the power of the second death over them...which suggest the power of physical death, the first death, still does reign over them, thus a glorified terrestrial inheritance.
It would explain the weeping and gnashing of teeth of those left behind for missing out on that first inheritance in becoming celestial by Him & having a place in the city of God.
The firstfruits will be like the angels, celestial as in they can never die and they do not marry, thus living in the city of God.
So when God's city comes down on earth to dwell among men for that 1000 year reign and thereafter, that is God expanding His kingdom of Heaven to have His city come to the earth for God to dwell among men.
Revelation 21:2 And I John saw
the holy city, new Jerusalem, coming down from God out of heaven, prepared as a bride adorned for her husband.3 And I heard a great voice out of heaven saying,
Behold, the tabernacle of God is with men, and he will dwell with them, and they shall be his people, and God himself shall be with them, and be their God.