When Jesus stood before Pontius Pilate, Pilate asked the Lord if he was, in fact, a king. This is the conversation that is recorded in John 18:
Then Pilate entered into the judgment hall again, and called Jesus, and said to him, Are you the King of the Jews?
Jesus answered him, Say you this thing of yourself, or did others tell it you of me?
Pilate answered, Am I a Jew? Your own nation and the chief priests have delivered you to me: what have you done?
Jesus answered, My kingdom is not of this world: if my kingdom were of this world, then would my servants fight, that I should not be delivered to the Jews: but now is my kingdom not from hence.
Pilate therefore said to him, Are you a king then?
Jesus answered, You say that I am a king. To this end was I born, and for this cause came I into the world, that I should bear witness to the truth. Every one that is of the truth hears my voice.
Pilate said to him, What is truth?
And when he had said this, he went out again to the Jews, and said to them, I find in him no fault at all.
Jesus said, "My kingdom is not of this world." The word translated "world" is the Greek word, "cosmos." It means pretty much the same as the English word world -- all of creation, all the physical things that can be seen by the human eye. This includes all of outer space and the rest of the universe, because if we could travel into other parts of the universe, we could conceivably see what is there with the human eye.
So, if his kingdom was not "of this world," where is it?
Jesus also said, "for this cause came I into the world." If he came into this world, where did he come from?
I have an old friend who is professor-emeritus of chemistry at a big university. Back in the seventies when I was in college and in daily contact with him, he was working on a paper entitled, The Spiritual Implications of Quantum Mechanics. That was the first time I heard of quantum theory, which -- as I understand it -- proposes that there are multiple dimensions, one that we can see and others that can't be seen. His theory was that if there are unseen dimensions that really exist, that leaves open the possibility that there are also creatures, like angels and demons, that occupy those dimensions. And if those creatures can travel freely from one dimension to another, they could at times interact with people in our world.
(If you want to see how that interaction might play out in a science fiction book, I invite you to read C.S. Lewis' space trilogy.)
When Jesus told Pontius Pilate, "You say that I am a king. To this end was I born, and for this cause came I into the world..." I believe he was almost talking to himself. Pilate did not understand what Jesus was talking about. But Jesus was reciting to himself the purpose of his life. He was born -- he came into our world from that other place -- "to this end." He came to die.
In the very beginning of our world, God gave dominion over the world to Man.
So God created man in his own image, in the image of God created he him; male and female created he them. And God blessed them, and God said to them, Be fruitful, and multiply, and replenish the earth, and subdue it: and have dominion over the fish of the sea, and over the fowl of the air, and over every living thing that moves on the earth. (Genesis 1:27, 28)
Man was the prince of this world, this dimension. Such was our birthright. But what happened to that birthright? Just before Jesus' arrest and execution, he told his disciples, "Now is the judgment of this world: now shall the prince of this world be cast out." (John 12:31) He was speaking of Satan. Satan became "the prince of this world." Why? Because we handed it over to him. When Adam sinned in the Garden of Eden, he relinquished his authority over this world -- this "cosmos" -- to the sworn enemy of the Creator -- Satan. Satan became the prince of this world.
But notice what Jesus said in that passage just quoted: "Now is the judgment of this world: now shall the prince of this world be cast out." The king has come. He will cast out the usurper, and return this world to its rightful owner -- Man. And which Man? The Man Jesus Christ.
Jesus laid aside the royalty of a King of all dimensions to come be one of us. He became a Man, and because he was a perfect Man, without the sin that condemned us all to enslavement to Satan, he reclaimed the birthright of all men from the usurper. He planted God's standard on that rocky hill outside Jerusalem. By laying down his life, he paid the lawful penalty every one of us owed. He paid it, he gained the right to reclaim what had been lost. He planted the flag of the Kingdom of God, there at the cross on which he died. And when he rose again on the third day, he took up that banner and led a host of captives out of hell.
We are part of that army. Every person alive or dead who has sworn fealty to the Lord Jesus Christ is part of the Kingdom of God. We reclaim the world lost to our enemy so long ago. We have authority over the fish of the sea, the fowl of the air, and every living thing that moves on the earth. This is why we can cast out demons, heal the sick, and command storms to be silent. Through what Jesus accomplished for us (something we could not do ourselves), we have dominion once again.
The Kingdom of God started on the hill of Calvary, but it stretches through time and space and claims hearts and souls. It is everywhere, and it is right here. It is unseen, but it impacts all that we see. The Kingdom of God is us.