How does the covenant of grace relate to the New Testament?

The New Testament reveals that the covenant of grace initiated in the Old Testament is fully realized in Jesus Christ. His life, death, and resurrection establish the new covenant that brings salvation to both Jews and Gentiles. In John 10, Jesus as the Good Shepherd illustrates the gathering of His flock, fulfilling the prophetic promise that those outside of Israel would also be brought into the family of God. The Apostle Paul further emphasizes in his letters that all God's promises find their 'yes' in Christ, ensuring that the covenant remains alive and effective through faith in Him.