Catechism of the Catholic Church
2816 In the New Testament, the word basileia can be translated by "kingship" (abstract noun), "kingdom" (concrete noun) or "reign" (action noun). The Kingdom of God lies ahead of us. It is brought near in the Word incarnate, it is proclaimed throughout the whole Gospel, and it has come in Christ's death and Resurrection. The Kingdom of God has been coming since the Last Supper and, in the Eucharist, it is in our midst. The kingdom will come in glory when Christ hands it over to his Father:
It may even be . . . that the Kingdom of God means Christ himself, whom we daily desire to come, and whose coming we wish to be manifested quickly to us. For as he is our resurrection, since in him we rise, so he can also be understood as the Kingdom of God, for in him we shall reign. 86
2817 This petition is "Marana tha," the cry of the Spirit and the Bride: "Come, Lord Jesus."
Even if it had not been prescribed to pray for the coming of the kingdom, we would willingly have brought forth this speech, eager to embrace our hope. In indignation the souls of the martyrs under the altar cry out to the Lord: "O Sovereign Lord, holy and true, how long before you judge and avenge our blood cm those who dwell upon the earth?" For their retribution is ordained for the end of the world. Indeed as soon as possible, Lord, may your kingdom come! 87
2818 In the Lord's Prayer, "thy kingdom come" refers primarily to the final coming of the reign of God through Christ's return. 88 But, far from distracting the Church from her mission in this present world, this desire commits her to it all the more strongly. Since Pentecost, the coming of that Reign is the work of the Spirit of the Lord who "complete[s] his work on earth and brings us the fullness of grace." 89
2819 "The kingdom of God [is] righteousness and peace and joy in the Holy Spirit." 90 The end-time in which we live is the age of the outpouring of the Spirit. Ever since Pentecost, a decisive battle has been joined between "the flesh" and the Spirit. 91
Only a pure soul can boldly say: "Thy kingdom come." One who has heard Paul say, "Let not sin therefore reign in your mortal bodies," and has purified himself in action, thought and word will say to God: "Thy kingdom come!" 92
2820 By a discernment according to the Spirit, Christians have to distinguish between the growth of the Reign of God and the progress of the culture and society in which they are involved. This distinction is not a separation. Man's vocation to eternal life does not suppress, but actually reinforces, his duty to put into action in this world the energies and means received from the Creator to serve justice and peace. 93
2821 This petition is taken up and granted in the prayer of Jesus which is present and effective in the Eucharist; it bears its fruit in new life in keeping with the Beatitudes. 94
English Translation of the Cathechism of the Catholic Church for the United States of America © 1997, United States Catholic Conference, Inc.