Now when He heard that John had been arrested, He withdrew into Galilee. And leaving Nazareth, He went and lived in Capernaum by the sea, in the territory of Zebulun and Naphtali, so that what was spoken by the prophet Isaiah might be fulfilled: “The land of Zebulun and the land of Naphtali, the way of the sea, beyond the Jordan, Galilee of the Gentiles—the people dwelling in darkness have seen a great light, and for those dwelling in the region and shadow of death, on them a light has dawned.” From that time, Jesus began to preach, saying, “Repent, for the kingdom of heaven is at hand.”
Jesus begins His ministry in Galilee. Why? To fulfil the Scriptures (vv. 14-16), from Isaiah 9:1-2. At the same time, John the Baptiser had been arrested. Jesus picks up where the Forerunner had left off to fulfil what John had begun, “Repent, for the kingdom of heaven has come near” (once again, not “is at hand”).
Jesus is the “great light” that “has dawned” in Galilee. Once again, this could be another reference to Malachi 4:2, the sun of righteousness. Jesus dawned first in His birth, then His ministry in Galilee, on the cross, from the grave, and then at His glorious return. Galilee was in a time of darkness, and Jesus dawned upon it as its great light. Indeed, it was a time of darkness.
Each Jewish sect had their own works righteousness under the Law. The poor and ill suffered greatly (worse than today). The tyranny of nobility. The oppression of the Roman Empire. We live in our own dark times, but these times were even darker. Jesus would shine a light upon their dark region in His miracle works as well as His preaching and teaching of the Gospel, which is His light that still shines today.