MARK 1.14-15: Now after John was arrested, Jesus came into Galilee, proclaiming the gospel of God, (15) and saying, “The time is fulfilled, and the kingdom of God is at hand; repent and believe in the gospel.” (ESV)
Mark writes in summary form that John the Baptist has now been taken out of his public ministry. Matthew and Luke provide the additional details that Herod had John arrested and locked up in prison, because John spoke against Herod taking his brother Philip’s wife, Herodias, to be his wife. So John’s ministry as the forerunner of Jesus had been completed, and it was a success.
As Jesus began to preach the gospel, He announced that the kingdom of God is at hand. This would be received as good news by many, because it meant that God’s kingdom will take authority over all other kingdoms. And the people of Israel despised the Roman government.
But the message of Jesus regarding the kingdom of God was not ever going to be about revolution against the Romans by fighting and insurrection. The good news about God’s kingdom is that a sinner can have a right relationship with God through Jesus. And no other kingdom can interfere with or destroy this fact.
When Jesus says, “the time is fulfilled”, He is saying that the “opportune” time has come. This means that in God’s order and timing of events, the exact right time to bring God’s kingdom on earth by the terms of the New Covenant has arrived, as promised in Jeremiah 31.31-37.
Galatians 4.4-5 says, “But when the fullness of time had come, God sent forth his Son, born of a woman, born under the law, (5) to redeem those who were under the law, so that we might receive adoption as sons.” (ESV). This fullness of time for God to send Jesus to bring redemption and establish the New Covenant is all in keeping with God choosing when He wanted to bring it to pass, as He worked through world events.
God’s kingdom on earth began all anew in Jesus. The living out of the Old Covenant by the children of Israel had failed, because of their rebellion against God and their unbelief. But now there is the good news – the “Gospel” – that a new relationship with God is available directly to all people everywhere in the world, by and through Jesus.