God explains his mission for his Servant (Isaiah 42:6b). The Father called his Servant to be a covenant for the people. A Biblical covenant that God makes is a solemn agreement between God and people to provide rescue for them and/or a relationship with them. The core of the covenant varies according to the covenant made. The core of the covenants made with Noah, Abraham, and David were God’s promises to each one. The first two had signs—something that testified to the reality of the covenant. The covenant with Noah had the sign of the rainbow and the one with Abraham had the sign of circumcision. The core of the law or old covenant was the law written on tablets of stone, the Ten Commandments. Its sign was the Sabbath (Exodus 31:12-18).
The core of the new or better covenant is a Person, the Lord Jesus Christ. Note carefully that Christ is the covenant (cf. Isaiah 49:8) as well as its Messenger (Malachi 3:1) and Mediator (Hebrews 9:15). Messiah, the Servant of the Lord, himself is the fulfillment of all that comes before him, and so we read here that he himself is the covenant. “In Christ alone my hope is found, He is my light, my strength, my song, This Cornerstone, this solid ground Firm through the fiercest drought and storm…” (Getty and Townend). The sign or evidence that a person is in the new covenant is the reception of the Holy Spirit when he or she believes in Jesus Christ (Acts 2:38).
God also called his Son to be a light for the nations (Gentiles). Notice carefully that not only does Christ bring light (Ephesians 5:13-14), but that he himself is the light (John 8:12; 9:5), as he is the covenant. Some have balked at the idea that Christ is the covenant. But that should give them no more concern than the truth that Jesus is the light for the nations. “Light” is a figurative way of saying “salvation” (Isaiah 49:6b). Matthew points this out in the ministry of Jesus (Matthew 4:16-17). Christ’s mission has a worldwide significance: “to the nations”. The people who are in covenant (“in Christ”) will include not only the believing Jews but believers from all nations (Ephesians 2:11-22; etc.) Read Jesus’ words (Luke 24:44-47).
Since Christ is our covenant and light, we have salvation in him. We have our relationship with God in him and through him. How can we be sure that we can draw near to God? Christ is our covenant relationship with God. How can we be certain of salvation? Christ is our light. If you are struggling about your relationship with God or with assurance of your salvation, refocus on Christ our covenant and light (cf. Hebrews 12:1-2).
Grace and peace, David