Now after John was put in prison, Jesus came to Galilee, preaching the gospel of the kingdom of God, 15 and saying, “The time is fulfilled, and the kingdom of God is at hand. Repent, and believe in the gospel.” Mark 1:14, 15 NKJV
“At hand” is an idiom, and in some uses, a prepositional phrase that means near in time and position. When Jesus kicked off His public ministry, preaching that the kingdom of God is at hand, announcing the beginning of God’s reign on earth and the forgiveness of sin. His message was the gospel (“good news”) of the kingdom because it offered freedom, justice, and hope to the poor; deliverance to the bound and oppressed; and, healing to the sick and diseased. The unequivocal message of Jesus’ ministry was that the kingdom of God is at here and now.
The time had been fulfilled because Jesus was operating on a prophetic time-table, i.e., it was His appointed time to begin His ministry because John the Baptist was decreasing and He was increasing (John 3:30). When time is fulfilled, everything in life (good, bad, or indifferent) happens at a preordained appointed time (Acts 1:6, 7; Gal. 4:4). But the good news is: when the King is on the scene, there is change in the air, if you repent and believe in the gospel. True repentance, (i.e., change of mind, to think differently, and afterthought), precedes real faith towards God (Heb. 6:1).
“At hand” is a kingdom that has already come, i.e., the kingdom of God. According to Jesus’ preaching, you’re not going to the kingdom, but the kingdom has come to you (Luke 17:21). After “Jesus went about all Galilee, teaching in their synagogues, preaching the gospel of the kingdom, and healing all kinds of sickness and all kinds of disease among the people” (Matt. 4:23), large crowds begin to follow Him; then He, from a mountain (Matt.5:1), begin to teach the multitude to pray: “Your kingdom come. Your will be done on earth as it is in heaven” (Matt. 6:10).
“At hand is a kingdom that can be seen (by faith) and entered into (John 3:5, 5, 12). If you’ve repented and believe in the gospel message, then by faith, see that God’s kingdom is already “at hand”—and as it is in heaven, enjoy the same here on earth. The kingdom of God is at hand!