2 Corinthians 1:20, Galatians 3:16, Romans 15:8
The Grand Summary
Paul's statement in 2 Corinthians 1:20 is one of the most sweeping in the entire New Testament: "For all the promises of God find their Yes in him. That is why it is through him that we utter our Amen to God for his glory."
All the promises. Not some. Not the specifically Messianic ones. All of them. Every promise God has made in the entirety of Scripture finds its "Yes" — its fulfilment, its confirmation, its guarantee — in Jesus Christ.
What This Means
The statement establishes Christ as the hermeneutical centre of all Scripture — the lens through which every promise is to be understood, the person in whom every promise is ultimately given.
The promises to Abraham — that his seed would bless all nations — find their Yes in Christ, the seed of Abraham (Galatians 3:16), through whom blessing flows to every people.
The promises to David — an eternal king from his line — find their Yes in Christ, the Son of David enthroned at the Father's right hand.
The promise of the new covenant — law written on the heart, full forgiveness, direct knowledge of God — finds its Yes in Christ, the mediator of the new covenant, and in the Spirit He poured out.
The promise of resurrection — the defeat of death — finds its Yes in Christ, the firstfruits of those who have fallen asleep.
The promise of the new creation — all things made new — finds its Yes in Christ, the one in whom new creation has already begun (2 Corinthians 5:17).
The Amen of the Church
Paul adds: "That is why it is through him that we utter our Amen to God for his glory." The "Amen" of the church's worship — our "so be it," our "yes and truly" — is not confidence in our own faithfulness. It is confidence in the faithfulness of Christ, in whom every promise is already secured.
This is the foundation of Christian assurance: not "I have kept my part of the covenant" but "Christ is the Yes to every promise God has made, and I am in Christ." The promises rest on Him. They cannot fail because He cannot fail.