The idea of kingship is a tricky issue in the modern world. Many people in Western culture, especially those who live in the United States, believe all kings are tyrants.
This is based on the experience of human kings who abused their power and lorded it over their subjects.
When Jesus is called, "king," the same imagery can come to the surface, raising the notion that Jesus is a king in the earthly sense.
Yet, even Jesus himself rejected this association with earthly kings.
Not an worldly king
Pope Benedict XVI pointed this out in an Angelus message he gave in 2008:
Today, the last Sunday of the liturgical year, we are celebrating the Solemnity of Our Lord Jesus Christ, King of the Universe. We know from the Gospels that Jesus refused the title of king when it was meant in the political sense, by the standards of the "rulers of the Gentiles" (Mt 20: 25).
Jesus did not want to be grouped with all the tyrant kings of the past or future, kings who were only kings for political gain.
At the same time, Jesus did not refuse the title of "king." He simply defined his kingship differently than the rest.
Pope Benedict XVI explains this alternative view of kingship:
On the other hand, during his Passion, he claimed a unique kingship before Pilate, who explicitly asked him "So you are a king?" and Jesus answered, "You say that I am a king" (Jn 18: 37); however just previously he had declared, "My kingship is not of this world" (Jn 18: 36). Christ's kingship is in fact a revelation and actuation of that of God the Father, who governs all things with love and justice. The Father entrusted to the Son the mission of giving mankind eternal life by loving it to the point of supreme sacrifice and, at the same time, conferred upon him the power of judging humanity, since he made himself Son of man, like us in all things (cf. Jn 5: 21-22, 26-27).
Jesus is above all the king of our hearts. He is not a demanding king, but a king who loves us, and calls us to a virtuous lifestyle, as Pope Benedict XVI writes:
[T]he Kingdom of God is not a matter of honors and appearances but, as St. Paul writes, it is "righteousness and peace, and joy in the Holy Spirit" (Rm 14: 17). The Lord has our good at heart, that is, that every person should have life, and that especially the "least" of his children may have access to the banquet he has prepared for all. Thus he has no use for the forms of hypocrisy of those who say: "Lord, Lord" and then neglect his commandments (cf. Mt 7: 21). In his eternal Kingdom, God welcomes those who strive day after day to put his Word into practice.
Jesus is a king, but not the king we might expect.