The Lord is King; let the peoples tremble;*
He sits between the cherubim; let the earth shake.
Why would the God of the universe take the title of king? This seems like such an earthly title below the divine presence but this is indeed how God wants us to relate with Him. He is King. Much of what Jesus did related to His kingship. Jesus hung on the cross accused of being a rival to Caesar and the king of the Jews. Indeed the kingship of God is vitally important for how we understand what God is doing.
The great theologian John Calvin comments that the kingship of Jesus leads to a divine governance. The people of the Church are rightly directed and governed by the Spirit of Christ. He leads them to bring about His justice and mercy. He gives the church vocation and organization. Perhaps even more significant is the way our divine King defends His church. He is a warrior king committed to our defense and victory even at His own expense. Sin and death and all the forces and powers of the world cannot stand against His mighty power. As our king, He wields this power to our defense. He rescues us from death and the grave. Indeed our God is king! Let us tremble before him.