When Pope Pius XI instituted the Feast of the Kingship of Our Lord Jesus Christ in 1925, he observed that "human society is tottering to its fall, because it has no longer a secure and solid foundation." It was his hope that, by Catholics seriously embracing the Kingship of Christ in their own lives and families, both privately and publicly, "society will at last receive the great blessings of real liberty, well-ordered discipline, peace and harmony." In short, the Kingship of Christ, His royal empire, is His dominion over all things in heaven and on earth, not just the hearts of men, but also "in the wills of men, for in him the human will was perfectly and entirely obedient to the Holy Will of God, and further by his grace and inspiration he so subjects our free-will as to incite us to the most noble endeavors." This is the public, or social reign of Jesus Christ as King. "Our Lord's regal office invests the human authority of princes and rulers with a religious significance; it ennobles the citizen's duty of obedience." (Quotes taken from the encyclical, Quas Primas.)
The great Irish priest, Fr. Denis Fahey, wrote the following in his book, The Social Rights of Our Divine Lord:
Student. What is the fundamental condition of the Kingship of Jesus Christ over society?Teacher. This condition consists in the explicit will of the Holy Trinity to give to Jesus Christ as man a true and absolute royal power. It is not a question of the rights of the Word of God, which are infinite, but of the rights and powers which God gives to the Sacred Humanity assumed by the Word.S. God has made known to us His Will in this matter?T. Undoubtedly. In the Encyclical of "Quas Primas" Pope Pius XI brings forward two proofs, indicating the Divine Will in this matter. He sets out the first proof thus:-"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' (Luke x.). 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 recognise His empire; by reason of the hypostatic union Christ has power over all creatures."
S. Explain the second doctrinal foundation of this truth taught by Pius XI.T. "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 those who forget what they have cost their Saviour 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' (1 Peter, i. 1819). We are no longer our own, for Christ has purchased us 'with a great price' (1 Cor. vi. 20); our very bodies are the 'members of Christ' (1 Cor. vi. 15)."
Getting back to Pope Pius XI, and Quas Primas:
Oh, what happiness would be Ours if all men, individuals, families, and nations, would but let themselves be governed by Christ! "Then at length," to use the words addressed by our predecessor, Pope Leo XIII, twenty-five years ago to the bishops of the Universal Church, "then at length will many evils be cured; then will the law regain its former authority; peace with all its blessings be restored. Men will sheathe their swords and lay down their arms when all freely acknowledge and obey the authority of Christ, and every tongue confesses that the Lord Jesus Christ is in the glory of God the Father."The holy pope is spelling out unity here.
In another encyclical of Pope Pius XI, Mortalium Animos, he specifies unity:
Unity can only arise from one teaching authority, one law of belief, one Christian Faith … There is but one way in which the unity of Christians may be fostered, and that is by fostering the return to the one true Church of Christ of those who are separated from it.Triumphalistic? Yes.
The faithful, moreover, by meditating upon these truths, will gain much strength and courage, enabling them to form their lives after the true Christian ideal. 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, Quas Primas