In the Gospels, Jesus repeatedly refers to the kingdom of God. It is His kingdom.
John 18: 36: Jesus answered, My kingdom is not of this world: if my kingdom were of this world, then would my servants fight, that I should not be delivered to the Jews: but now is my kingdom not from hence.
That is absolutely correct. But Christ is still the king. Just as an earthly king may have brothers and sisters, so are we the brothers and sisters of our King.
1Ti 6:14-16 (RSV) I charge you to keep the commandment unstained and free from reproach until the appearing of our Lord Jesus Christ; and this will be made manifest at the proper time by the blessed and only Sovereign, the King of kings and Lord of lords, who alone has immortality and dwells in unapproachable light, whom no man has ever seen or can see. To him be honor and eternal dominion. Amen.
And what will "the appearing of our Lord Jesus Christ" be like?
Rev 19:11-16 (RSV) Then I saw heaven opened, and behold, a white horse! He who sat upon it is called Faithful and True, and in righteousness he judges and makes war. His eyes are like a flame of fire, and on his head are many diadems; and he has a name inscribed which no one knows but himself. He is clad in a robe dipped in blood, and the name by which he is called is The Word of God. And the armies of heaven, arrayed in fine linen, white and pure, followed him on white horses.
From his mouth issues a sharp sword with which to smite the nations, and he will rule them with a rod of iron; he will tread the wine press of the fury of the wrath of God the Almighty.
On his robe and on his thigh he has a name inscribed, King of kings and Lord of lords.
The "Lamb" (Jesus) is also identified as the King of kings and Lord of lords. (Rev 17:14)
Rev 1:4-6 (NKJV) John, to the seven churches which are in Asia: Grace to you and peace from Him who is and who was and who is to come, and from the seven Spirits who are before His throne, and from Jesus Christ, the faithful witness, the firstborn from the dead, and the (A) ruler over the kings of the earth. To Him who loved us and washed us from our sins in His own blood, and (B) has made us kings and priests to His God and Father, to Him be glory and dominion forever and ever. Amen
(A) Jesus Christ is called ruler of the kings of the earth as the King of Kings.
(B) We have been made kings who are subordinate to the King of Kings and Lord of Lords.
Jesus is the King of the Kingdom of God.
Mat 28:18 (NKJV) And Jesus came and spoke to them, saying, “All authority has been given to Me in heaven and on earth.
He is our king and the Body of Christ IS the church.
Col 1:24 I now rejoice in my sufferings for you, and fill up in my flesh what is lacking in the afflictions of Christ, for the sake of His body, which is the church,
I can't really disagree with most of what you wrote. I'm just offering an alternate perspective.
iakov the fool