In the Paul VI liturgy, the feast of Christ the King has been relocated to the last Sunday before Advent (this year, November 22), thus situating its celebration in a more explicitly eschatological and apocalyptic context. This new emphasis is also reflected in the expanded title of the feast in the Paul VI calendar: D. N. Iesu Christi universorum Regis ("Our Lord Jesus Christ King of the Universe").
Of course, this eschatological/apocalyptic/cosmic dimension was not completely lacking in the original feast of Christ the King, as established by Pope Pius XI in 1925. It was implicit in the dating of the feast in relation to All Saints Day, the original eschatological/apocalyptic feast par excellence, which brings the Church's annual cycle to a fitting conclusion in the contemplation of the final harvest of the Kingdom, of which Christ's earlier resurrection was "the first fruits" (1 Corinthians 15:20).
But Pius XI's feast, assigned to the Sunday before November 1 (this year, October 25), was less ostensibly cosmic in its focus and more explicitly social in its emphasis. Instituted as the Holy Year of 1925 was coming to its end, with the "Roman Question" still unresolved and in the tragic aftermath of the pointless First World War, which had represented what Pope Benedict XV had called "the suicide of civilization," the feast of Christ the King reflected a decidedly contemporary, less future-oriented preoccupation. This was also reflected in Pius XI's prescription of the annual renewal of the Act of Consecration to the Sacred Heart on the feast of Christ the King.
There is, of course, no contradiction between Paul VI's Christ the King who reigns at the right hand of his Father and will come again to judge the world and Pius XI's emphasis on Christ the King ruling over and calling to account the principalities and powers of this world right now. They are actually quite complementary, and both deserve liturgical and devotional emphasis.
So, even though the feast is no longer celebrated this weekend, we would still do well to recall what Pius XI wanted us to reflect upon annually on this last Sunday in October.
If to Christ our Lord is given all power in heaven and on earth; if all men, purchased by his precious blood, are by a new right subjected to his dominion; if this power embraces all men, it must be clear that not one of our faculties is exempt from his empire. He must reign in our minds, which should assent with perfect submission and firm belief to revealed truths and to the doctrines of Christ. He must reign in our wills, which should obey the laws and precepts of God. He must reign in our hearts, which should spurn natural desires and love God above all things, and cleave to him alone. He must reign in our bodies and in our members, which should serve as instruments for the interior sanctification of our souls, or to use the words of the Apostle Paul, as instruments of justice unto God (Pope Pius XI, Encyclical Letter Quas Primas, 33)