The Old Testament introduces the idea that the Kingdom of God involves a King who rules, a people who are ruled and a sphere where this rule is recognized (Ex 19:4-6); but the phrase "Kingdom of God" is introduced only in the New Testament.

"You yourselves have seen what I did to the Egyptians, and how I lifted you up on eagles' wings and brought you to Myself. So now then, if you will indeed listen to My voice and keep My covenant, then you shall be My treasured possession among all the peoples, for all the earth is Mine; and you shall be to Me a kingdom of priests and a holy nation.' These are the words that you shall speak to the sons of Israel." (Ex 19:4-6, LSB)

1. Take a moment to examine Adam and Eve, and fill out the table.

Then Yahweh God said, "Behold, the man has become like one of Us to know good and evil; and now, lest he send forth his hand and take also from the tree of life and eat and live forever"⁠ - therefore Yahweh God sent him out from the garden of Eden, to cultivate the ground from which he was taken. So He drove the man out; and at the east of the garden of Eden He stationed the cherubim and the flaming sword which turned every direction to guard the way to the tree of life. (Gen 3:22-24, LSB)

2. How large is the Promised Land? Despite Moses' warning to the nation of Israel of what would happen if they fail in their covenant commitments, it ultimately happens.

On that day Yahweh cut a covenant with Abram, saying,
"To your seed I have given this land,
From the river of Egypt as far as the great river, the river Euphrates: (Gen 15:18, LSB)

And all the nations will say, 'Why has Yahweh done thus to this land? Why this great burning anger?' Then men will say, 'Because they forsook the covenant of Yahweh, the God of their fathers, which He cut with them when He brought them out of the land of Egypt. And they went and served other gods and worshiped them, gods whom they have not known and whom He had not apportioned to them. Therefore, the anger of Yahweh was kindled against that land, to bring upon it every curse which is written in this book; and Yahweh uprooted them from their land in anger and in fury and in great wrath, and He cast them into another land, as it is this day.' (Deut 29:24-28)

3. With the birth of Jesus, the angel Gabriel signals the inauguration of the Kingdom of God by explicitly linking the birth to the covenant God made with David (Luke 1:31-33).

And behold, you will conceive in your womb and bear a son, and you shall name Him Jesus. He will be great and will be called the Son of the Most High, and the Lord God will give Him the throne of His father David, and He will reign over the house of Jacob forever, and there will be no end of His kingdom." (Luke 1:31-33, LSB)

4. Jesus introduces the idea that the Kingdom of God is exclusively associated with salvation through Christ. To enter the Kingdom, one must be "reborn" (John 3:1-21).

Jesus answered and said to him, "Truly, truly, I say to you, unless one is born again he cannot see the kingdom of God." Nicodemus said to Him, "How can a man be born when he is old? Can he enter a second time into his mother's womb and be born?" Jesus answered, "Truly, truly, I say to you, unless one is born of water and the Spirit he cannot enter into the kingdom of God. That which has been born of the flesh is flesh, and that which has been born of the Spirit is spirit. Do not marvel that I said to you, 'You must be born again.' (John 3:3-7, LSB)

5. Whose kingdom do the disciples see?

For this you know with certainty, that no one sexually immoral or impure or greedy, who is an idolater, has an inheritance in the kingdom of Christ and God. (Eph 5:5, LSB)

I solemnly charge you in the presence of God and of Christ Jesus, who is to judge the living and the dead, and by His appearing and His kingdom: (2 Tim 4:1, LSB)

for in this way the entrance into the eternal kingdom of our Lord and Savior Jesus Christ will be abundantly supplied to you. (2 Pet 1:11, LSB)

6. Jesus reveals to the disciples that the Kingdom of God is ushered in suddenly and without warning with the return of the Son of Man (Mark 13:1-37; 14:62; Luke 17:22-37). The arrival of the Kingdom will be unexpected and apocalyptic.

Then the seventh angel sounded, and there were loud voices in heaven, saying, "The kingdom of the world has become the kingdom of our Lord and of His Christ, and He will reign forever and ever." (Rev 11:15, LSB)

7. The Kingdom is realized.

Then I saw a new heaven and a new earth; for the first heaven and the first earth passed away, and there is no longer any sea. And I saw the holy city, new Jerusalem, coming down out of heaven from God, made ready as a bride adorned for her husband. (Rev 21:1-2, LSB)

And nothing defiled, and no one who practices abomination and lying, shall ever come into it, but only those whose names are written in the Lamb's book of life. (Rev 21:27, LSB).

Then he showed me a river of the water of life, bright as crystal, coming from the throne of God and of the Lamb, in the middle of its street. On either side of the river was the tree of life, bearing twelve kinds of fruit, yielding its fruit every month; and the leaves of the tree were for the healing of the nations. And there will no longer be any curse; and the throne of God and of the Lamb will be in it, and His slaves will serve Him; and they will see His face, and His name will be on their foreheads. And there will no longer be any night, and they will not have need of the light of a lamp nor the light of the sun, because the Lord God will illumine them, and they will reign forever and ever. (Rev 22:1-5, LSB)

The Kingdom of Jesus Christ reverts back to the Kingdom of God:

Then comes the end, when He hands over the kingdom to the God and Father, when He has abolished all rule and all authority and power. For He must reign until He has put all His enemies under His feet. The last enemy to be abolished is death. For He has put all things in subjection under His feet. But when He says, "All things are put in subjection," it is evident that He is excepted who put all things in subjection to Him. And when all things are subjected to Him, then the Son Himself also will be subjected to the One who subjected all things to Him, so that God may be all in all. (1 Cor 15:24-28, LSB)