In Matthew 4:12-17 (you can listen to the sermon here), we learn that Jesus is the light of the world that has dawned in Galilee and will spread to Judea and Samaria, and the ends of the earth. Jesus is the fulfillment of the Messianic promise that Matthew quotes directly from Isaiah 9:1-2. In Matthew 4:17, Christ heralds the commencement of his public ministry that is the coming of the kingdom of heaven down to earth.
God’s promise to us who have repented and believed is that we, even us Gentiles, have become part of God’s heavenly kingdom by faith in the crucified Christ alone. This means that we too have become part of God’s church, the earthly institutional expression of the kingdom on heaven on earth. And it is in the church, especially when we are gathered for public worship each Lord’s Day that God assures us and even enables us to taste of the powers of the age to come.