Matt 3:2

3:2 Repent. The first command of both John the Baptist and Jesus (4:17). Repentance is not just sorrow for sin but a decisive change, a turning away from sin and to a life of obedience. “Repent” translates the Old Testament call to Israel to “return” to faithfulness to the covenant. It does not mean self-punishment, depression, or remorse. Judas was sorrowful and distressed (27:3) but he did not repent. See “Repentance” at Acts 26:20.

kingdom of heaven. The message of John the Baptist introduces the theme of Jesus’ teaching. Mark and Luke call it the “kingdom of God” (4:17; cf. Mark 1:15). The kingdom or the reign of God is what the Old Testament prophets awaited: God’s display of His sovereignty in the redemption of His people. John and Jesus proclaimed that the time of waiting was over and the King Himself had come. With the death and resurrection of Jesus and the spread of the good news to all nations, the Old Testament promises of God have been largely fulfilled for us, although we still await their complete realization when Christ returns in judgment (ch. 13 and notes).

is at hand. The beginning of God’s work is the basis for the command to repent.