It makes sense when we understand the city of saved people in heaven are the spiritual body of Christ; living souls without human form. They are the New Jerusalem the city that shall come down from heaven with the Lord. They are spirits (not flesh & blood) of men made perfect. They come with the Lord to give life to our body of flesh changed from mortal to immortal and corruptible to incorruptible. Because without spirit there is not life.
John 6:63 (KJV) It is the spirit that quickeneth; the flesh profiteth nothing: the words that I speak unto you, they are spirit, and they are life.
John 14:3 (KJV) 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.
Hebrews 12:22-24 (KJV) But ye are come unto mount Sion, and unto the city of the living God, the heavenly Jerusalem, and to an innumerable company of angels, To the general assembly and church of the firstborn, which are written in heaven, and to God the Judge of all, and to the spirits of just men made perfect, And to Jesus the mediator of the new covenant, and to the blood of sprinkling, that speaketh better things than that of Abel.
2 Corinthians 5:8 (KJV) We are confident, I say, and willing rather to be absent from the body, and to be present with the Lord.
1 Corinthians 15:44 (KJV) It is sown a natural body; it is raised a spiritual body. There is a natural body, and there is a spiritual body.
Revelation 20:4 (KJV) And I saw thrones, and they sat upon them, and judgment was given unto them: and I saw the souls of them that were beheaded for the witness of Jesus, and for the word of God, and which had not worshipped the beast, neither his image, neither had received his mark upon their foreheads, or in their hands; and they lived and reigned with Christ a thousand years.
Revelation 21:9-10 (KJV) And there came unto me one of the seven angels which had the seven vials full of the seven last plagues, and talked with me, saying, Come hither, I will shew thee the bride, the Lamb's wife. And he carried me away in the spirit to a great and high mountain, and shewed me that great city, the holy Jerusalem, descending out of heaven from God,
Revelation 21:23-24 (KJV) And the city had no need of the sun, neither of the moon, to shine in it: for the glory of God did lighten it, and the Lamb is the light thereof. And the nations of them which are saved shall walk in the light of it: and the kings of the earth do bring their glory and honour into it.