Honestly, I couldn't watch the whole thing. I got a bit bored after about 30 minutes. I just don't understand all the pomp and circumstance. Totally my fault. But I do know this. Based on everything I've read about the monarchy, Charles may be the king, but his functions are limited to various official, ceremonial, and diplomatic duties. He actually takes very little direct participation in government. He may be the head of state, but all true political power rests in the prime minister and the cabinet. The monarch can act only on their advice. One article I read said the king functions as nothing more than a "mascot" of the UK. I think it's much more significant than that. However, it is true that he has no independent constitutional authority. The monarchy that was once an absolute monarchy is now a constitutional monarchy. Today, the king's powers may be used only in accordance with the laws enacted by Parliament.
Jesus often spoke of the kingdom of God. What do you need to have a kingdom? Well, you need a king, and you need subjects. Jesus, of course, is our king. Hence what we want most as his subjects is to see the advancement of his kingdom. It's not, "Lord, I've got my agenda and I want you to condone it." Nope. The church is not a constitutional monarchy. It's an absolute monarchy. Jesus calls the shots.
Furthermore, Jesus rules over all. Contrast that with the British Commonwealth. The British Commonwealth is a political association of 56 member states. Most of them are former territories of the British Empire. They include Australia, Canada, Cyprus, Ghana, Malawi, Nigeria, Singapore, and Uganda. Charles, however, is the king of only 15 member states, while 36 other members are republics and 5 others have different monarchs. On the other hand, Jesus is Lord of all 195 nations in the world today, and churches are kingdom embassies in the world. Of course, before we can serve him, he must be king in our hearts:
King of my life, I crown Thee now; Thine shall the glory be.
Just think. We believers are in the coronation business! We are out to make Christ the Lord of all. One day we will "bring forth the royal diadem and crown him Lord of all." Of course, the world does not want this. That's because it doesn't want him. But be sure of this: "Jesus shall reign where'er the sun doth its successive journeys run."
In the meantime, a Christian is a mere pilgrim on this earth because he is a citizen of a heavenly commonwealth (Phil. 3:20). Every member of this holy nation is meant to be an ambassador beseeching men and women to be reconciled to God, who offers an Emancipation Proclamation to every slave of sin and a Declaration of Dependence as we learn to live in constant dependence on him for our every need.
I think it's important to remind people of this from time to time.