Mat 4:17 Repent: for the kingdom of heaven is at hand.
Change your minds! It has gotten near. What? The realm of the skies.
This short verse has several surprises. It illustrates a common theme, that the translations of Christ's words emphasize "sin" much more than he actually did.
The word translated as "repent" has nothing to do with sin or, generally, with religion or asking for forgiveness. The Greek word translated as "repent" has a primary meaning of to understand something after the fact, with the sense of seeing it is too late. Is specific meaning is to "understand afterward," as seeing the truth after a mistake is made. From this idea, it comes to mean to change your mind, shifting your perspective. This is in the form of a command.
The subject of the sentence, the Greek word translated as "kingdom" but it has a lot of meanings related to royalty. It means the authority to rule or reign of a monarch. It can mean either the place that is ruled, the people who are ruled, or a female ruler (since the word's form here is feminine). It can mean the capital city or an empire of the ruler's castle. Our English word "basilica," meaning the seat of power for a bishop comes from this word. Generally, it refers to the concept of hereditary rule, the passing of authority from one generation to the next.
The word translated as "heaven" means literally "the skies." It encompasses everything above the surface of our world, that is, the rest of the universe. It included the sun, moon, planets, and stars, which were ethereal objects, closer to abstract ideas and universal ideas than material objects because they did not fall to earth. This idea of the heavenly or universal extended to the spiritual and the divine realms. If beings lived in the sky, they were spirits, demons, and gods. These beings were "universal" in the sense that they could travel everywhere, from heaven to earth. More to the point, "the heavens" for regular people were the unreachable, mysterious territory that people could see in space and time but never touch, feel, or understand.
The "reign of the skies" is different than the "kingdoms of the world." See this article for more information on this phrase.
There is no verb for "is" in this verse. Nor is there an adverb meaning "at hand."
The Greek word translated as "is at hand" is a word that Christ invented. It is a verb created from an adverb that means "near" or "at hand". It refers both to physical places and time. This means that the verb means "to bring near", "to approach", "to bring up to," and "to be close." However, it is in a tense that indicates that this action has completed. The KJV translation makes it sound like something is coming in the future but the form of the verb indicates something that has already happened. Christ (and John the Baptist before him, who used the exact same words) were not warning about a change that was coming. The sense is "has come near." This verb appears before the phrase "kingdom of heaven".
As far as this kingdom of understanding drawing near or being joined with the world of men, Christ always refers to this, not as something that happens at a specific time, but something that is always being culminated right now. Since the general assumption here is that Christ's words apply to us now as much as they applied to his contemporaries, this would mean that the process is still as completed today as it was 2,000 years ago.
The Spoken Version:
He walk down the street announcing. "Turn yourselves around! Turn yourselves around!"
As they turned to see what he was talking about, he gestured to the sky with both hands.
"Because the realm of the stars...." he said, as if answering a question. "Is getting awfully close."
Μετανοεῖτε, (2nd pl pres imperat act) "Repent," is from metanoeo, which literally means "to perceive afterward", "to perceive too late", "to change one's mind", "to change one's purpose," and "to repent."
ἤγγικεν (3rd perf act sg ind) "Is at hand" is from eggizo, which means "to bring near", "to join one things to another," to draw near," and "to approach." This word does not appear in the Perseus dictionary. It comes from a verb from ἐγγύς, eggus, which means 1) (of place) "near", "nigh", "at hand," 2) (of time) "nigh at hand" 3) (of numbers) "nearly", "almost", "coming near," and 4) (of relationship) "akin to."
ἡ βασιλεία (noun sg fem nom) "The kingdom" is from basileia which means "kingdom", "dominion,""reign", "queen", "princess", "palace", "hereditary rule", "kingly office," (passive) "being ruled by a king," and "reign."