A Christian reading of Scripture affirms that the biblical authors do not tell us everything everywhere all at once. Things build, and that takes time. The doctrine of Scripture includes the teaching of progressive revelation.
The Story of God’s redemptive plan is a long story, encompassing sixty-six books and unfolding across millennia. Told in two Testaments, the biblical story is from a Divine Author who has inspired the writings we read therein. Growth in understanding the Scripture will mean paying attention to how the Old and New Testaments relate. Furthermore, the relationship between the two Testaments is a major interest in the task of doing biblical theology—and you know we care about that task here at this site.
Have you ever read Augustine’s famous statement about how the Old and New Testaments connect? He said, “The New is in the Old concealed; the Old is in the New revealed” (Questions on the Heptateuch, 2.73).
Augustine’s words concisely describe what Christians call “the unity” of Scripture and its “progressive revelation.”
The Old Testament contains prophecies and patterns of Christ. It contains the mystery of the church and the plan of God to bring the nations to salvation through the work of his Son. In other words, the Old Testament conceals the New. By God’s design, the Old Testament was incomplete.
The New Testament is not an appendix or an epilogue to the Old. The New Testament books are about fulfillment, about promises kept. As Augustine put it, “the Old is in the New revealed.” The climax of the Old Testament is the New Testament. Mysteries are declared, and shadows are swallowed by light.
Christians are New Covenant members, yes. But New Covenant believers must not be only New Testament people. We must be whole-Bible people! The early church proclaimed Christ from the Old Testament. According to Paul, all of Scripture is God-breathed and is useful for teaching and training (2 Tim. 3:16).
Augustine’s insight is a restatement of what Jesus and the apostles taught about the Old Testament (see, for example, Luke 24:25–27, 44–47; 1 Cor. 10:1–11; 1 Pet. 1:10–12). Consider several implications of Augustine’s claim:
We need the Old Testament to understand the New, and we need the New Testament to understand the Old. We need to read forward and backward.
The New Testament sheds light on the Old Testament storyline, covenants, prophecies, and mysteries. What was concealed in the Old has been revealed in the New, in the person and work of Christ and in Christ’s commission to his church.
The Divine Author’s plan did not fail in the Old Testament but continued through the Old Testament and into the New. This unity of the two Testaments is a basic presupposition for a Christian reading of Scripture.
All of Scripture is Christian Scripture. While the New Testament is shorter than the Old and easier to understand, we nevertheless need to be students and readers of the Old. After all, the Old Testament contains the sufferings and glories of Christ (1 Pet. 1:10–12).
The progressive revelation of Scripture displays the faithfulness of God, the epic of his redemptive plan, and the coherence of the biblical Story.