The New Testament primarily uses the Old Testament to show that God is bringing his promises to fulfillment. God’s history of revelation and redemption comes to a climax in a manner that is continuous with the Old. When we think of the use of the Old Testament in the New Testament there are a number of analogies that writers have used over the years. One of the more helpful analogies is that of a seed that has grown to fruition having now blossomed in the fulfillment of the plan of God.
Consider the composition of a seed. On the outside, it does not look like the full and final tree in fruition. However, the seed contains all the genetic material that will be ‘revealed’ as time progresses and a climax is reached. As we exam a seed, we understand at least in part what it will become. We can know what flower will come from the seed, but when it blossoms, we will see a greater beauty now present.
Similarly, the Old Testament’s use of the New Testament shows a continuity between promise and fulfillment. A classic example is Peter’s preaching in Acts 2. He is very clear that precisely what is promised in Acts 2 has now been fulfilled. Peter in effect says “this that you see” is “that which was promised.” Even more, as Peter continues with the use of Psalm 16, he clearly shows how the Old Testament Psalm could not have truly been fulfilled in David since David died, was buried, his body decayed, and he was never resurrected. With respect to Christ’s fulfillment, Peter could again say “this is that.” The events were prophesied all along, but at least for Peter, seeing it happen helped him understand what God had said long ago.