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

The fulfillment of God's covenant through Christ is evidenced in His life, death, and resurrection. He was called in righteousness (Isaiah 42:6) to serve as the perfect high priest and the ultimate sacrifice for sin. Through His obedience, He fulfilled the demands of the law (Romans 3:21-22), making it clear that salvation is found in Him alone. God's declaration that He will not alter the covenant (Psalm 89:34) underscores the assurance we have in Christ's work, confirming that all God's promises are yes and amen in Him (2 Corinthians 1:20). Therefore, our confidence in the covenant rests upon His perfect faithfulness and righteousness.