The royalty of Jesus Christ has his base in the fact that Jesus Christ is the Head of the New Humanity reconciled with God (2 Color 5, 17 -19).
Saint Paul says that Jesus Christ is the descendant of David according to the human nature: "He was descended from David according to the flesh (Rm 1, 3).
But he was constituted Son of God in all his power by the Holy Spirit in the moment of his resurrection of among the dead (Rm 1, 4 -5).
He is a king that is never imposed by force and in his kingdom just is only one law: the love. Here are Jesus’ words: “I give you a new commandment:
"Love each other as well as I love you. People will know that you are my disciples if you love one another" (Jo 13, 34 -35).
This means that the power of Jesus is the power of love. In other words Jesus Christ just wants to reign in union with us.
Love is proposed never imposed. The love is a dynamics that tends for the communion and the total share.
This is the reason why Jesus shared with us his royalty, says the First Letter of Saint Peter:
"However, you are a chosen people, sacred priesthood, Nation of kings, gathered and acquired, in order to proclaim the marvels of God.
In fact he called us and led us out of darkness into his amazing light" (1 Pd 2, 9).
The The kingdom of God is love. No one has greater love than the person who gives his life for his friends" (Jo 15, 12 -13).
When the strength of a kingdom is the love, then this kingdom is communion and fraternity.
Before dying, Jesus said that Kingdom of God was in the people heart (Lc 17, 21). In fact, while Jesus lived in the earth, the Kingdom of God as an organic communion Man and God was emerging just inside Jesus.
In other words as Jesus lived in the middle of people, the Kingdom of God was emerging in the middle of crowd.
But in the moment of his death and resurrection, Jesus passed from the coordinates of the space and time, to the universal interiority, becoming more inside us than ourselves.
When he resurrected Jesus united us organically to the mystery of Holy Trinity through Holy Spirit.
From this moment the Kingdom of God starts to emerge within us as always emerged within Jesus.
In other words, with Jesus' resurrection the Kingdom of God passed to the inner maximum of the Universe.
This means that after his resurrection, Jesus always comes to us starting from inside and the Holy Spirit optimized our organic union with God qualifying us qualifying us to reign with Jesus Christ. In Communion With You