I think that the new Jerusalem could very well be the perfected Church:
Rev 21:2 And I saw the holy city, new Jerusalem, coming down out of heaven from God, prepared as a bride adorned for her husband. (ESV)
The Church is sometimes referred to as the Bride of Christ:
Eph 5:31 “Therefore a man shall leave his father and mother and hold fast to his wife, and the two shall become one flesh.”
Eph 5:32 This mystery is profound, and I am saying that it refers to Christ and the church. (ESV)
Rev 19:7 Let us rejoice and exult and give him the glory, for the marriage of the Lamb has come, and his Bride has made herself ready;
Rev 19:8 it was granted her to clothe herself with fine linen, bright and pure”— for the fine linen is the righteous deeds of the saints.
Rev 19:9 And the angel said to me, “Write this: Blessed are those who are invited to the marriage supper of the Lamb.” And he said to me, “These are the true words of God.” (ESV)
Rev 21:9 Then came one of the seven angels who had the seven bowls full of the seven last plagues and spoke to me, saying, “Come, I will show you the Bride, the wife of the Lamb.”
Rev 21:10 And he carried me away in the Spirit to a great, high mountain, and showed me the holy city Jerusalem coming down out of heaven from God, (ESV)