Christ and the Covenants: Christmas and Biblical Theology

The miracle of Christ become man is rooted in ancient promises. Comprehending this gives Christmas—indeed the Christian faith—a richer texture than one can scarcely imagine.

The genealogy of Matthew 1 directly connects the line of Christ with the reign of David. In the Old Testament, a young, unknown boy becomes the sovereign of Israel, God’s people. In the New Testament, a young, unknown boy instructs rabbinic teachers, an early glimpse of his kingship over the people of God, the new Israel constituted by the sacrificial work of Christ. Matthew continues throughout his Gospel to connect Christ with the Davidic kingship of God’s people, a kingship whose unique and otherworldly character is displayed by an atoning death, even death on a cross (Matthew 26).

Many Christians struggle to know how to put the covenants—old and new—together. Christmas is a rare time in the life of many churches when evangelicals dwell on the Old Testament. The joyful truth is that we may connect the old and new covenants not simply in December, but all year round. What the old covenant promises and looks ahead to, the new covenant fulfills and realizes. Through New Testament books like 2 Corinthians and Hebrews, we learn that our great high priest has come. He has brought an end to sacrifices, has become our Sabbath rest, has given us a claim on the new heavens and new earth, and has fulfilled the old covenant law.

Jesus does not come only to offer salvation. He does so, but the salvation he offers is not a heavenly flash sale—a pop-up operation set up for a weekend to accomplish redemption. The deliverance offered by the blood of Christ is nothing other than the realization of God’s covenantal promises. The seed of the woman comes, so many years after Adam’s fall, and offers himself as the Passover lamb, and the goat released on the Day of Atonement who takes the sins of the people far into the wilderness, so far those sins cannot ever be found (Lev. 16).

The blood of Christ is the blood of the new covenant (Luke 22:20). Christ is the law of his people; to follow God in the era of the new covenant is to follow the God-man and his teaching. We reverence the old covenant law, finding in it revelation of the divine will, but recognize that the new covenant is a better covenant, and thus that the moral law we now follow is bound up in the teachings of Christ (Hebrews 8:6). Christ loved the law, but he did not place his disciples under old covenant practice, but rather brought them into a new law, a law of love revealed in him (John 13:34).

The deliverance that Christ offers in his person and work is breathtaking. Many believers boggle at how to integrate the old and new covenants; doubtless there are many tough matters to sort out. But we rest in this: Christ is the key to understanding the covenants. Christ is the fulfillment of the promises of God. There are still dimensions of realization we await, but when trying to sort out how we live here and now, we have a key.

This key is Christ.

Christmas lets many of us dip our toes in these impossibly deep waters. But the believer need not only integrate the covenants in December. Preachers have the year-round potential to weave a seamless biblical storyline through their expository messages. Yes, our modern cultural context matters for preaching; yes, the “original meaning” of the text is of great importance to us; but alongside historical-grammatical considerations, the major context that preachers must search out is the biblical-theological context, helping the congregation understand how the story of Scripture is one story with many related chapters. How is this particular text foretold, or fulfilled, in the old and new covenants? What here is being promised? What here is coming to realization? How is Christ the Lord of this passage? Making these kind of connections will give the faith of the normal Christian tremendous confidence, depth, and hope. The God who kept his promises by sending us an incarnate Christ will keep them once more, and will soon send us the one who will undo every wicked thing.

There is much that we must put together carefully in engaging the culture and prosecuting public theology. This is our burden—a joyful one—at the Center for Public Theology. But we cannot miss this: Christians do not only offer certain texts to our neighbors, to our public square. We offer a true story, a crucified and resurrected Savior, and a Scripture bursting with the power and wisdom of God.

Christmas is not merely a fun season. Christmas is a miraculous season. But it is a season whose depth we only understand—and love—when we understand that which it fulfills, and that which it promises.

We have seen great things; but greater things still we shall see.

Merry Christmas.