We forget this simple fact: “everything in the heavens and on earth belongs to” the Lord God. God is “head over all.” Eventually, all things are summed up in Christ, who is the second person of the Trinity, who is the Lord God. Ezra sums this up nicely:
“Yours, LORD, is the greatness and the power and the glory and the splendor and the majesty, for everything in the heavens and on earth belongs to You. Yours, LORD, is the kingdom, and You are exalted as head over all.”
Notice what else — ha, besides everything — belongs to the Lord God: greatness, power, glory, splendor, majesty, and the kingdom.
Jesus says to His disciples and to the people, ‘Behold, the kingdom of God is at hand.’ Being the Lord God, Jesus indicates the kingdom is present in Him. He might as well say, ‘Behold, I Am the kingdom of God.’