“Now after John was arrested, Jesus came into Galilee, proclaiming the gospel of God, and saying, “The time is fulfilled, and the kingdom of God is at hand; repent and believe in the gospel.” (Mark 1:14)
Jesus began preaching the gospel once John was imprisoned. He proclaimed that the Kingdom of God had arrived in Him, that He was the promised Messiah. His message was that God was now fulfilling the promises He had made to Abraham and his descendants. Jesus proclaimed that He is the fulfillment of God’s promises. Jesus, like John and Jonah called people to repent, to turn away from sin and to turn to God. Like Jonah, Jesus knew sinners would repent and follow Him, but unlike Jonah, Jesus preached with joy and compassion for, as God incarnate, He is loving and merciful.
This is why Jesus came manifesting God’s power, righteousness, mercy and love. Jesus preached with authority and performed signs, wonders, miracles to add further power to His teaching. So the people believed in Him.
The best part of the Good News was Jesus Himself. He proclaimed that the Kingdom of God had arrived and that the Lord was reconciling the world unto Himself in His own person. Yet the people who heard Him preach, even the disciples He called did not understand how he was going to do this. And yet this is the greatest news anyone can hear for it fills us with the Holy Spirit who sustains us with strength and perseverance that enables us to keep on going in the midst of a world filled with pain and strife. And the great thing is, He has called us to spread the good news.