ENCYCLICAL OF POPE PIUS Xl DECEMBER 11, 1925
DsZ 3675 (7.) It has long been a common custom to give to Christ the metaphorical title of "King," because of the high degree of perfection whereby he excels all creatures. So he is said to reign "in the hearts of men,"......He reigns, too, in the wills of men,......He is King of hearts, too, ......But if we ponder this matter more deeply, we cannot but see that the title and the power of King belongs to Christ as man in the strict and proper sense too. For it is only as man that he may be said to have received from the Father "power and glory and a kingdom," since the Word of God, as consubstantial with the Father, has all things in common with him, and therefore has necessarily supreme and absolute dominion over all things created.
DsZ 3676 (13.) The foundation of this power and dignity of Our Lord is rightly indicated by Cyril of Alexandria. "Christ," he says, "has dominion over all creatures, a dominion not seized by violence nor usurped, but his by essence and by nature." His kingship is founded upon the ineffable hypostatic union. From this it follows not only that Christ is to be adored by angels and men, but that to him as man angels and men are subject, and must recognize his empire; by reason of the hypostatic union Christ has power over all creatures. But a thought that must give us even greater joy and consolation is this that Christ is our King by acquired, as well as by natural right, for he is our Redeemer. Would that they who forget what they have cost their Savior might recall the words: "You were not redeemed with corruptible things, but with the precious blood of Christ, as of a lamb unspotted and undefiled." We are no longer our own property, for Christ has purchased us "with a great price"; our very bodies are the "members of Christ."
DsZ 3677 (14.) Let Us explain briefly the nature and meaning of this lordship of Christ. It consists, We need scarcely say, in a threefold power which is essential to lordship.......and moreover it is a dogma of faith that Jesus Christ was given to man, not only as our Redeemer, but also as a law-giver, to whom obedience is due. Not only do the gospels tell us that he made laws, but they present him to us in the act of making them. Those who keep them show their love for their Divine Master, and he promises that they shall remain in his love. He claimed judicial power as received from his Father, when the Jews accused him of breaking the Sabbath by the miraculous cure of a sick man. "For neither doth the Father judge any man; but hath given all judgment to the Son." In this power is included the right of rewarding and punishing all men living, for this right is inseparable from that of judging. Executive power, too, belongs to Christ, for all must obey his commands; none may escape them, nor the sanctions he has imposed.
DsZ 3678 (15.) This kingdom is spiritual and is concerned with spiritual things. That this is so the above quotations from Scripture amply prove, and Christ by his own action confirms it. On many occasions, when the Jews and even the Apostles wrongly supposed that the Messiah would restore the liberties and the kingdom of Israel, he repelled and denied such a suggestion. When the populace thronged around him in admiration and would have acclaimed him King, he shrank from the honor and sought safety in flight. Before the Roman magistrate he declared that his kingdom was not of this world. The gospels present this kingdom as one which men prepare to enter by penance, and cannot actually enter except by faith and by baptism, which, though an external rite, signifies and produces an interior regeneration. This kingdom is opposed to none other than to that of Satan and to the power of darkness. It demands of its subjects a spirit of detachment from riches and earthly things, and a spirit of gentleness. They must hunger and thirst after justice, and more than this, they must deny themselves and carry the cross.
(16.) Christ as our Redeemer purchased the Church at the price of his own blood; as priest he offered himself, and continues to offer himself as a victim for our sins. Is it not evident, then, that his kingly dignity partakes in a manner of both these offices?
DsZ 3679 (17.) It would be a grave error, on the other hand, to say that Christ has no authority whatever in civil affairs, since, by virtue of the absolute empire over all creatures committed to him by the Father, all things are in his power. Nevertheless, during his life on earth he refrained from the exercise of such authority, and although he himself disdained to possess or to care for earthly goods, he did not, nor does he today, interfere with those who possess them. Non eripit mortalia qui regna dat caelestia.
(18.) Thus the empire of our Redeemer embraces all men. To use the words of Our immortal predecessor, Pope Leo XIII: "His empire includes not only Catholic nations, not only baptized persons who, though of right belonging to the Church, have been led astray by error, or have been cut off from her by schism, but also all those who are outside the Christian faith; so that truly the whole of mankind is subject to the power of Jesus Christ." Nor is there any difference in this matter between the individual and the family or the State; for all men, whether collectively or individually, are under the dominion of Christ. In him is the salvation of the individual, in him is the salvation of society. "Neither is there salvation in any other, for there is no other name under heaven given to men whereby we must be saved."