The main theme of Jesus’ preaching is the Kingdom of God, or the Kingdom of Heaven, but the Kingdom is notoriously hard for us moderns to define, so we usually skip over that part. I once got involved with an organisation that talked quite a bit about the Kingdom of God, and used it as a kind of slogan and rallying cry, without bothering to define it. It always bothered me that they go so hyped up about an undefined goal.
One of the strengths of N. T. Wright’s Jesus and the Victory of God is that he gives the theme of the Kingdom the emphasis it deserves. Jesus was a first century Jew preaching to other first century Jews in language they would understand.
Here, according to Wright, is what a first century Jew would think when he heard a prophet preaching the coming the Kingdom of God:
It meant, first and foremost, that God himself would become the King of Israel, and put the world aright. That meant a political change, that God would toss out the Romans, Herod, and the current priestly clan that ran the Temple. It meant that God would return to the Temple, manifesting his presence the way he had in the days of Solomon. It meant, probably, the return of the Davidic monarchy, the return of diaspora Jews, and the conversion of the gentiles to the worship of the true God. Finally, it meant the religious reform of the people, who would then live as true Jews were meant to live. This Kingdom would be the climax of the history of Israel.
First century Christians also talk about the Kingdom, but they define it differently: the Kingdom has already been established, though it is still in its early phases, growing into eventual fulfillment. The enemies conquered were not the Romans, but the devil, sin, and death. It is not located in the Holy Land, but it extends to the whole world.
The symbols of the Jewish hope for the Kingdom, the Temple, the Monarchy, the land, are abandoned in the Christian vision. What remains is the Jewish framework of monotheism, God’s chosen people, and the belief in God’s action in the world. It is not a new story, but a new act in the unfolding of the same old tale. It is not a hope but an incipient reality.
The key to understanding the preaching of Jesus is to understand it as being the catalyst that transformed the first vision of the Kingdom of Heaven into the second.