Jesus, the King of all hearts, has earned His sovereignty over our hearts by the limitless quality of His love for each human being. He surrenders Himself into our hands, in the divine madness of unrequited love, and we slaughter Him.
And it is thus that He has broken the claim that the powers of this world had on us: the claims of money, comfort, status, control, "self-care."
In that excellent encyclical "Quas primas" that instituted today's Feast of Christ the King, Pope Pius XI highlights the Scriptural claim that Jesus rules by more than natural right. Yes, as God, Jesus has plenary authority over every creature. Yes, even as man, Jesus enjoys universal sovereignty, by virtue of the hypostatic union of His human nature with His divine Sonship.
But what really moves Pope Pius is the theodramatics, not the metaphysics, of Christ's authority: "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."
Redemption.
This is well attested in the Resurrection narratives, and it is crucial to the soteriology of the New Testament.
Pius cites I Peter 1:18-19: "You were not redeemed with corruptible things, but with the precious blood of Christ, as of a lamb unspotted and undefiled."
Redemption means that the divine economy of salvation radically disrupts the economy of this world. Pius goes on to sharpen Saint Paul's observations in I Corinthians 6: "We are no longer our own property, for Christ has purchased us 'with a great price'; our very bodies are the 'members of Christ.'"
We are no longer our own property. Not even our bodies belong to us. Love has displaced all other claims. Love has the final claim on us. We don't get to say, "this much and no more," before love's imperium. That is what the sovereignty of Jesus means.
Love is stronger than death. Love conquers all. By dying.
The authority of Jesus has everything to do with His love-death on our behalf. What He says at the end of Saint Matthew's Gospel, "all authority in heaven and on earth has been given to Me" (28:18), He explains at the beginning of the Book of Revelation: "Do not be afraid; I am the First and the Last and the Living One. I became dead, and behold, I am living into the ages of the ages and I have the keys of death and of hell" (Rev 1:17-18).
It's because Jesus has pierced the veil of death by being slaughtered that Love has authority even in this world of terminal lovelessness.
And what this slaughtered Priest-King wants is subjects willing, in turn, to fall in the service of love: "To Him Who loves us and freed us from our sins by His blood, and made us a kingdom, priests serving His God and Father, to Him be glory and dominion forever and ever. Amen" (Rev 1:5-6).
A kingdom of priests is a kingdom of martyrs to unilateral, unrequited Love. With such an army, the King would rule every heart.