How do we know Jesus Christ is the fulfillment of God's promises?

Isaiah prophesied about the coming of Christ, identifying Him as a child born and a son given to us, whose government and peace will never end (Isaiah 9:6-7). This is an affirmation of God's covenantal faithfulness through the line of David. The fulfillment of these prophecies is evidenced in the New Testament, particularly through genealogies that trace Jesus' heritage back to David. Moreover, Christ's life, death, and resurrection embody the ultimate realization of God's promises for reconciliation and salvation, indicating that all God's plans are achieved through Him.