God promised king David that he would have a son who would rule on his throne forever. “The Lord also declares to you that the Lord will make a house for you. When your days are complete and you lie down with your fathers, I will raise up your descendent after you, who will come forth from you and I will establish his kingdom. He shall build a house for my name, and I will establish the throne of his kingdom forever."
The historical promises to the Jewish people are also filled with the eternal promises to all those who God calls. Jesus, the son of David & the Son of God, is both messiah and king. King is not a metaphor here. Jesus is truly a King and he is the King of kings because he is the Lord. All kings must find their definition of King in the person of Jesus. The more they conform to Jesus the more they resemble a real king.
Revelation, the last book in the Bible speaks of the lamb as King. Speaking of evil humanity, evil leaders, and evil that rejects the kingship of Christ, John writes:
These will wage war against the Lamb, and the Lamb will overcome them, because he is the Lord of lords and King of kings, and those who are with him are the called and chosen and faithful. (Revelation 17:14)
There is so much hope in that last sentence, “those who are with him are the called and chosen and faithful. This is all God’s doing, united with Christ, and called by Christ, chosen by him and faithful because of his keeping power. It is Jesus, the King, who has died for us and redeemed us and keeps us.