What is Biblical Theology?
Seeing Christ in the Old Testament
Job and the great fish
One of the key themes in the New Testament is the idea of “fulfillment.” The Greek word, πληρόω, playro’o, appears over 20 times, usually with the formula, “all this took place to fulfill what the Lord had spoken by the prophet,” or some variation of that. The Greek word literally means “to fill up what is lacking.” Think of the imagery of water being poured into an empty cup. The “cup” is waiting to be “filled.” This is the idea behind playro’o.
Solomon composing Proverbs
Jesus plays off this “fulfillment” motif when he references Old Testament figures as precursors to his own ministry. For example, in Matthew 12:41, Jesus says, “someone greater than Jonah is here.” And in the next verse, “someone greater than Solomon is here.” So that Jonah and Solomon are types or molds of a future fulfillment figure, of which he is claiming is himself.
Adam and Eve in the Garden
This fulfillment theme is also present in the Epistles. In Ephesians 5, when Paul is giving counsel on marriage, he ends his exposition with this conclusion, “this mystery is profound, and I am saying that it refers to Christ and the church.” Paul is drawing a narrative arc, starting in Genesis 2:24, with the marriage of Adam and Eve in the Garden, progressing with Israel as the wayward bride of God (see Hosea), and finally ending with the marital union of Christ and the church. It’s a breathtaking tour of Scripture, marshaling all the various stages of redemptive history, in order to tell the gospel as an unfolding story.
Paul concludes that the shape of this narrative arc was a “mystery” – hidden for ages past, but now revealed in Christ. This is the essence of Biblical Theology. It’s mapping out the various themes that began in Genesis (like kingship, marriage, city), tracing them through the history of Israel, culminating in Christ and the church, and reaching its final fulfillment in Revelation.
This is not a novel way to read Scripture. Augustine famously described the relationship between Old and New Testaments as “the new is in the old concealed; the old is in the new revealed.” There is an organic relationship between the Old Testament and the New Testament, like an acorn is to a mature oak tree. There is progressive growth and development, so that the final shape is hinted at in the early stages, but all the essential elements are already there.
In formal theological terms, this is called Biblical Theology or Covenant Theology. It gives us a paradigm for reading the OT, not as moral parables (a la Aesop's Fables), but as pictures of salvation in Christ. It informs how we read the Old Testament, even in those stories where the New Testament does not explicitly spell out how Christ is the ultimate story behind the stories. Indeed, to read the Old Testament through the lens of the gospel is how the Bible authors themselves understand Scripture.
If you would like to learn more, here are a few good resources:
The Jesus Storybook Bible, Sally Lloyd-Jones (difficulty level: easy)
According to Plan: The Unfolding Revelation of God in the Bible, Graeme Goldsworthy (medium)
Preaching Christ in All of Scripture, Edmund Clowney (medium)
Biblical Theology, Geerhardus Vos (advanced)
Preaching Christ from the Old Testament, Sidney Greidanus (advanced)
Image captions:
“Jonah and the Whale” engraving by George Bernard (1911)
“King Solomon writing Proverbs” by Gustave Dore (1883)
“Adam and Eve in Paradise” by Lucas Cranach the Elder (1533)