1. We read in the Constitution Lumen Gentium of the Second Vatican Council that "believers in Christ (God) has willed to call them into the Holy Church, which . . . prepared in the history of the people of Israel and in the Old Covenant . . . was manifested by the outpouring of the (Holy) Spirit' (Lumen Gentium, 2). We devoted the previous catechesis to this preparation of the Church in the Old Covenant, in which we saw that, in Israel's progressive awareness of God's plan through the revelations of the prophets and the facts of its own history, the concept of a future kingdom of God, far higher and more universal than any prediction of the fate of the Davidic dynasty, was becoming increasingly clear. Today we turn to the consideration of another historical fact, dense with theological significance: Jesus Christ begins his messianic mission with the proclamation: "The time is fulfilled and the kingdom of God is at hand" (Mk 1:15). Those words mark the entrance "into the fullness of time", as St Paul would say (cf. Gal 4:4), and prepare the passage to the New Covenant, founded on the mystery of the redemptive incarnation of the Son and destined to be an eternal Covenant. In the life and mission of Jesus Christ, the kingdom of God is not only "near" (Lk 10:9), but is already present in the world, already acting in human history. Jesus himself says it: "The kingdom of God is in your midst" (Lk 17:21).

2. The difference in level and quality between the time of preparation and the time of fulfilment - between the Old Covenant and the New Covenant - is made known by Jesus himself when, speaking of his forerunner John the Baptist, he says: "Amen, I say to you, among those born of women there has not arisen one greater than John the Baptist; nevertheless the least in the kingdom of heaven is greater than he" (Matthew 11: 11). John, from the banks of the Jordan (and from his prison), certainly contributed more than anyone else, even more than the ancient prophets (cf. Lk 7:26-27), to the immediate preparation of the ways of the Messiah. However, he remains in a sense still on the threshold of the new kingdom, which entered the world with the coming of Christ and is in the process of manifestation with his messianic ministry. Only through Christ do men become the true "children of the kingdom": that is, of the new kingdom far superior to that of which the contemporary Jews considered themselves the natural heirs (cf. Mt 8:12).

3. The new kingdom has an eminently spiritual character. To enter it, one must be converted and believe the Gospel, freeing oneself from the powers of the spirit of darkness, submitting to the power of the Spirit of God that Christ brings to men. As Jesus says: "If I cast out demons by the power of the Holy Spirit, surely the kingdom of God has come among you" (Matt 12:28; cf. Lk 11:20).

The spiritual and transcendent nature of this kingdom is also expressed in the linguistic equivalent we find in the Gospel texts: "Kingdom of Heaven". A wonderful image that gives a glimpse of the origin and end of the kingdom - the "heavens" - and the very divine-human dignity of the One in whom the Kingdom of God is historically realised with the Incarnation: Christ.

4. This transcendence of the Kingdom of God is given by the fact that it originates not from a merely human initiative, but from the plan, design and will of God Himself. Jesus Christ, who makes it present and implements it in the world, is not just one of the prophets sent by God, but the Son consubstantial with the Father, who became man through the Incarnation. The kingdom of God is thus the kingdom of the Father and his Son. The kingdom of God is the kingdom of Christ; it is the kingdom of heaven that has opened on earth to allow men to enter this new world of spirituality and eternity. Jesus affirms: "Everything has been given to me by my Father . . . and no one knows the Father except the Son and he to whom the Son wishes to reveal him" (Mt 11:27). "For as the Father has life in himself, so he has granted the Son to have life in himself; and he has given him power to judge, because he is the Son of man" (Jn 5:26-27).

Together with the Father and the Son, the Holy Spirit also works for the realisation of the Kingdom already in this world. Jesus himself reveals this: the Son of man "casts out devils by the Spirit of God", and because of this "the kingdom of God has surely come among you" (Mt 12:28).

5. But while the Kingdom of God takes place and develops in this world, it has its purpose in "heaven". Transcendent in its origin, it is also so in its end, which is attained in eternity, provided we are faithful to Christ in our present life and throughout the unfolding of time. Jesus warns us of this when he says that, in accordance with his power to "judge" (Jn 5:27), the Son of Man will command at the end of the world to take "out of his kingdom all scandals", that is, all iniquities committed even within the realm of Christ's kingdom. And "then," Jesus adds, "the righteous will shine like the sun in their Father's kingdom" (Matt 13:41, 43). It will then be the full and final realisation of the "kingdom of the Father", to which the Son will send the elect saved by him in virtue of the Redemption and through the work of the Holy Spirit. The messianic kingdom will then reveal its identity with the Kingdom of God (cf. Mt 25:34; 1 Cor 15:24).

There is therefore a historical cycle of the reign of Christ, the Incarnate Word, but the alpha and omega of this reign, and indeed one would say the background in which it opens, lives, develops and reaches its full fulfilment, is the "mysterium Trinitatis". We have already said, and will see again in due course, that the "mysterium Ecclesiae" is rooted in this mystery.

6. The point of passage and connection from one mystery to the other is Christ, who already in the Old Covenant was foretold and awaited as a Messiah-King with whom the Kingdom of God was identified. In the New Covenant, Christ identifies the kingdom of God with his own person and mission. In fact, he not only proclaims that, with him, the kingdom of God is in the world, but teaches to "leave all that is most dear to man for the kingdom of God" (cf. Lk 18:29-30) and, at another point, to leave all this "for his name's sake" (cf. Mt 19:29), or "for my sake and for the sake of the gospel" (Mk 10:29).

The kingdom of God is thus identified with the kingdom of Christ. It is present in him, and in him it is realised. And from him it passes, by his own initiative, to the Apostles, and through them to all who will believe in him: "I prepare a kingdom for you, as the Father has prepared it for me" (Lk 22:29). It is a kingdom that consists in an expansion of Christ himself in the world, in human history, as new life that is drawn from him and communicated to believers by virtue of the Holy Spirit-Paraclete, sent by him (cf. Jn 1:16; 7:38-39 15:26; 16:7).

7. The messianic kingdom, implemented by Christ in the world, is revealed and its meaning definitively clarified in the context of the passion and death on the cross. Already at the entry into Jerusalem an event takes place, arranged by Christ, which Matthew presents as the fulfilment of a prophetic prediction, that of Zechariah about the "king riding on a donkey, a colt son of a donkey" (Zech 9:9; Matt 21:5). In the prophet's mind, Jesus' intent, and the evangelist's interpretation, the donkey meant meekness and humility. Jesus was the meek and humble king entering the Davidic city, where with his sacrifice he would fulfil the prophecies about true messianic kingship.

This kingship becomes very clear during the interrogation Jesus underwent at Pilate's tribunal. The accusations made against Jesus are "that he stirred up the . . . people, prevented them from giving tribute to Caesar, and claimed to be Christ the King" (Lk 23:2). Therefore Pilate asks the accused if he is king. And here is Christ's answer: "My kingdom is not of this world; if my kingdom were of this world, my servants would have fought lest I should be delivered up to the Jews; but my kingdom is not of here". The evangelist narrates that "then Pilate said to him: - So you are king? - Jesus answered: - You say it: I am king. For this I was born, and for this I came into the world: to bear witness to the truth. Whoever is of the truth hears my voice" (Jn 18:36-37).

8. It is a declaration that concludes the whole ancient prophecy that runs through the history of Israel and becomes fact and revelation in Christ. Jesus' words make us grasp the gleams of light that pierce the darkness of the mystery condensed in the trinomial: Kingdom of God, Messianic Kingdom, People of God summoned in the Church. In this wake of prophetic and messianic light, we can better understand and repeat, with a clearer understanding of the words, the prayer taught to us by Jesus (Mt 6:10): "Thy Kingdom come". It is the kingdom of the Father, which entered the world with Christ; it is the messianic kingdom that through the work of the Holy Spirit develops in man and in the world to ascend into the bosom of the Father, in the glory of heaven.

[Pope John Paul II, General Audience 4 September 1991]