“Jesus began to preach, and to say, Repent: for the kingdom of heaven is at hand” (Matt 4:17)

Barnes’ Notes on the Bible

Repent ye – Repentance implies sorrow for past offences; a deep sense of the evil of sin as committed against God and a full purpose to turn from transgression and to lead a holy life. A true penitent has sorrow for sin, not only because it is ruinous to his soul, but chiefly because it is an offence against God…. It is produced by seeing the great danger and misery to which it exposes us; by seeing the justice and holiness of God;…. There are two words in the New Testament translated “repentance,” one of which denotes a change of mind, or a reformation of life; and the other, sorrow or regret that sin has been committed. The word used here is the former, calling the Jews to a change of life, or a reformation of conduct.

The kingdom of heaven is at hand – The phrases kingdom of heaven, kingdom of Christ, kingdom of God, are of frequent occurrence in the Bible. They all refer to the same thing. The prophets had told of a successor to David that should sit on his throne . The Jews expected a great national deliverer. The language in which they were accustomed to describe this event was retained by our Saviour and his apostles. Yet they early attempted to correct the common notions respecting his reign. This was one design, doubtless, of John in preaching repentance. Instead of summoning them to military exercises, and collecting an army, which would have been in accordance with the expectations of the nation, he called them to a change of life; to the doctrine of repentance – a state of things far more accordant with the approach of a kingdom of purity.

As that kingdom was one of purity, it was proper that the people should prepare themselves for it by turning from their sins, and by bringing their hearts into a state suitable to his reign.

In accordance with the teachings of our Master, Mrs. Eddy writes in Science and Health page 16,
“Thy kingdom is come; Thou art ever-present.”