The Kingdom of God and the Kingdom of Heaven are, essentially, synonymous, yet not entirely. Reading in Scripture about the Kingdom of God, we observe a wide geography: the Kingdom of God is within us; the Kingdom of God approaches humanity through repentance and faith in the Gospel; the disciples glimpsed a portion of the Kingdom of God on the Mount of Transfiguration; "Of such is the Kingdom of God," Christ says of children; the Kingdom of God belongs to the poor in spirit. This list could continue, but I will provide just one more definition from the Apostle Paul: "The Kingdom of God is not eating and drinking, but righteousness and peace and joy in the Holy Spirit."
All that pertains to the Kingdom of God applies equally to the Kingdom of Heaven, but the word "heavenly" itself points specifically to the heavens.
To be frank, I have never been interested in the geographical coordinates of the Kingdom of Heaven. For me, it suffices that it exists. I admit there are people who, traveling to an exotic resort, have no idea where it is and care little about it; they bought a ticket, booked a tour, and head to the airport. This brings to mind Fonvizin's "The Minor": "The coachman will take us there!" Naturally, I do not advocate ignorance—maps should be studied—but a geographical map of the Kingdom of Heaven does not exist, so I content myself with faith in what Christ has said.
Paul speaks of the third heaven, yet this raises counter-questions: where is the first, where the second? Solomon says that heaven—heaven of heavens—does not contain God. Where is this "heaven of heavens"? Paul also says we shall be caught up on clouds to meet the Lord in the air—this image too I find difficult to imagine; clouds hardly seem like a solid foundation.
In the letter to the Hebrews, it is affirmed that Christ entered heaven itself. What did the author mean: some supergiant star or distant galaxy, or something immaterial? Scripture deliberately does not give us the coordinates of the Kingdom of Heaven because descriptions of heavenly things often exceed our comprehension and produce greatly distorted understanding. Consider, for instance, Ezekiel's wheel—I understand intellectually that it is something extraordinarily beautiful and perfect, yet imagining how it functions and moves is extremely difficult. I have tried, but in vain; I conjure only a monster. But a monster only in my mind...
Or take the golden streets of paradise? To me, a walk barefoot on green grass would be nicer. Yet these are purely our material perceptions. In reality, seeing those golden streets, we will not be able to tear our eyes away from such beauty and will once again convince ourselves of our pathetic attempts to understand the heavenly and spiritual, which have no analogues on earth.
So we make the first conclusion: the Kingdom of God or Kingdom of Heaven is not illusory, not virtual, but the most real reality that is. Christ speaks of it as an existing kingdom. It is the object of deep faith for Christians of all generations.
Now, regarding how to enter and become a citizen of this kingdom. This question is no less important than the first and perhaps even more urgent, for here something depends on humans themselves. To become a citizen of the Kingdom of Heaven is simultaneously simple and difficult. It is simple because there are no complex formulas, no tangled instructions, no unattainable prices, no required merits.
What is there, then? There is an invitation—heartfelt, persistent, yet not pushy. Jesus Christ came to earth to open the door leading to heaven, and He declares with authority: "I am the door: by me if any man enter in, he shall be saved, and shall go in and out, and find pasture."
What does this mean? It means that entry to the Kingdom of Heaven is through Him. He is the Door! If you have need of salvation and desire to enter the Kingdom of Heaven, then you approach the door that leads there. To approach the door is halfway. You must resolve to knock. How often does it happen that a person approaches a cherished door but lacks courage to knock and leaves empty-handed?
During my military service, I found the address of a presbyter in a strange city. I found the street, the house, entered the entryway, and stood at the door. I raised my hand to the bell, but hesitantly lowered it: "How can I show up at his door? He doesn't know me; he may be busy; I feel awkward." These and other thoughts chilled my resolve, and the bell button remained untouched. So I left the entryway with nothing... (Later we did meet, and there was no need for embarrassment.)
Approaching the Door-Christ, one must resolve to knock—that is, to ask, to pray, to repent. And He, in turn, will never refuse nor slam the door in irritation before our nose. All this hesitation is inspired by he who does not wish your salvation.
The first to knock at this Door was a thief, crucified on a cross beside Christ. And miraculously—he was received! If people beneath the cross heard this, they surely cursed in fury: "He killed, robbed, thieved, violated—and now he's in paradise?!" Their logic, strangely as it seems, is often close to ours. People more often crave vengeance than forgiveness. But God does not act thus! And this is the greatest grace—salvation by faith!
The other thief—he did not knock; he furiously pounded and shouted: "You are not real!" "If You are Christ, save Yourself and us!" One does not break into the door of salvation with demands and cries; one enters with repentance and bowing before God.
Thus, Christ is the Door to heaven, and it stands open! To open it, Christ as a lamb was slain, crucified, and rose again. Some doors open easily and smoothly, some with effort and creaking, others very heavily, with great struggle. This door had not opened since Adam, and Christ endured much to open it.
Jesus says of Himself: "I am the way, the truth, and the life; no one comes to the Father except through Me." John 14:6
Paul writes of Him: "For through Him we both have access by one Spirit to the Father." Ephesians 2:18
The letter to the Hebrews declares: "Therefore, brethren, having boldness to enter the holiest by the blood of Jesus, by a new and living way which He consecrated for us, through the veil, that is, His flesh." Hebrews 10:19-20.
The veil to the Holy of Holies, as it were the door to paradise—always closed. Except for one man, no one had the right to enter there. But suddenly the veil is torn with a noise. This is no simple curtain, not even a heavy theater curtain. Researchers say the temple veil was the thickness of a hand's breadth, and to tear it was nearly impossible. Yet it is torn from top to bottom—Christ opened the doors of paradise. And not only opened them but urgently calls: "Come to Me..."
We make the second conclusion: entry to paradise is quite simple. You need not register and wait years; you need not earn or deserve; no feats or self-mortification are required. You need only believe the invitation and come to Christ.
And finally, where lies the difficulty? The difficulty for humans is that entering the Kingdom of Heaven is too simple.
"What, is that really all? Just come and receive? That's not how it works!"
"I am not a pauper; I need no alms. I will earn and deserve myself."
"I do not need a Savior; I have something to answer God with."
Such reasoning greatly complicates, rather makes impossible, entry into the Kingdom of God.
But Christ still stands at the closed door of the heart and knocks... while He still knocks, while the Door to paradise is still open, while... Hear, inhabitants of earth, this invitation! Accept it and become citizens of the Kingdom of Heaven! Do not be late!
