Jesus is the royal Son of David, of whom it was prophesied by the angel at his birth:
He will be great, and will be called the Son of the Most High; and the Lord will give to him the throne of his father David, and he will reign over the house of Jacob forever; and of his kingdom there will be no end (Lk 1:32-33).
Through his sufferings as the Christ, Jesus achieved everlasting kingship and lordship over all creation. He has become “King of kings and Lord of lords,” sharing this title with God the Father Himself (Deut 10:17; Dan 2:47; Rev 19:16). As a man, Jesus Christ is King of the Kingdom of God.
Christ came for no other reason than to bring God’s kingdom to men. His very first public words are exactly those of his forerunner, John the Baptist: “Repent for the kingdom of heaven is at hand” (Mt 3:2, 4:17).
All through his life Jesus spoke of the kingdom. In the sermons such as the Sermon on the Mount and the many parables, he told of the everlasting kingdom.
Blessed are the poor in spirit for theirs is the kingdom of heaven…
Blessed are they who are persecuted for righteousness sake for theirs is the kingdom of heaven.
He who does these commandments and teaches them shall be called great in the kingdom of heaven.
But seek ye first the kingdom of heaven and its righteousness, and all things will be yours as well.
Not everyone who says to me, “Lord, Lord,” shall enter the kingdom of heaven, but he who does the will of my Father who is in heaven (Mt 5-7).
The mustard seed, the leaven, the pearl of great price, the lost coin, the treasure in the field, the fishing net, the wedding feast, the banquet, the house of the Father, the vineyard… all are signs of the kingdom which Jesus has come to bring. And on the night of His last supper with the disciples He tells the apostles openly:
You are those who have continued with me in my trials; as my Father appointed a kingdom for me, so do I appoint for you that you may eat and drink at my table in my kingdom, and sit on thrones judging the twelve tribes of Israel (Lk 22: 28-30; Reading of the Vigil of Holy Thursday).
Christ’s kingdom is “not of this world” (Jn 18:31). He says this to Pontius Pilate when being mocked as king, revealing in this humiliation His genuine divine kingship. The Kingdom of God, which Christ will rule, will come with power at the end of time when the Lord will fill all creation and will be truly “all, and in all” (Col 3:11). The Church, which in popular Orthodox doctrine is called the Kingdom of God on earth, has already mysteriously been given this experience. In the Church, Christ is already acknowledged, glorified, and served, as the only king and lord; and His Holy Spirit, whom the saints of the Church have identified with the Kingdom of God, is already given to the world in the Church with full graciousness and power.
The Kingdom of God, therefore, is a Divine Reality. It is the reality of God’s presence among men through Christ and the Holy Spirit. “For the Kingdom of God… means… peace and joy and righteousness in the Holy Spirit” (Rom 14:17). The Kingdom of God as a spiritual, divine reality is given to men by Christ in the Church. It is celebrated and participated in the sacramental mysteries of the faith. It is witnessed to in the scriptures, the councils, the canons, and the saints. It will become the universal, final cosmic reality for the whole of creation at the end of the ages when Christ comes in glory to fill all things with Himself by the Holy Spirit, that God might be “all and in all” (1 Cor 15:28).