Where systematic theology is more like a street map, identifying the arterials and intersections, biblical theology is more like a topographical map—with the peaks and valleys, rivers, and oceans.

For example, a systematic theology will scan the whole of Scripture for a coherent doctrine of Christ (christology), while a biblical-theological sweep will highlight the organic development of revelation concerning Christ from promise to fulfillment. 

Biblical theology tells the story

Princeton’s early twentieth-century biblical theologian Geerhardus Vos nicely explained, “In Biblical Theology the principle is one of historical, in Systematic Theology it is one of logical construction. Biblical Theology draws a line of development. Systematic Theology draws a circle.” Biblical theology rivets our attention to the historical development of various themes, pointing up discontinuities as well as continuities: the “many times and many ways” in which “God spoke to our fathers by the prophets, but in these last days he has spoken to us by his Son” (Heb 1:1–2). To change the metaphor, biblical theology tells the story, while systematics unpacks the implications and the logical connections. 

We need both. 

You need the summary and the details

To do biblical theology properly, we need to attend closely to the text, moving back and forth constantly between the whole and the parts. It’s not just systematicians who must be careful not to impose their system on the text; biblical theologians can just as easily “over-read” their sweeping surveys and miss the trees for the forest.

Biblical theology is essential if we’re going to feel the Bible’s own pulse and follow its unfolding plot.

Let’s say we want to focus on a biblical-theological sweep of the doctrine of the church. Realizing revelation follows the actual history of God’s works, we begin with Adam and Eve. There, the church is identified with an earthly kingdom. There is no distinction between cult (worship) and culture (civic life). Yet after the fall, they’re exiled “east of Eden.” Their work is now common rather than holy; the kingdom is identified with those who “call on the name of the Lord.” And yet they go out with a promise of a coming Redeemer.

Hope in future salvation

The kingdom of God was also identified with a specific nation again when God gave Israel his covenant at Mount Sinai, but that too ended in human unfaithfulness and the covenant people were exiled—yet, once more, with hope in the promise of a future salvation.

Finally, Christ fulfilled those promises and his new covenant community was the expansion of Israel, united to him as its covenant head. When Christ returns, the whole earth will be his church and kingdom. For now, though, it is a kingdom of grace with a mission not to “rule” and “subdue” the enemies of God, but to proclaim the forgiveness of sins through Word and sacrament in the power of the Spirit.

Systematic theology needs biblical theology

Biblical theology is essential if we’re going to feel the Bible’s own pulse and follow its unfolding plot. Without it, systematic theology can easily succumb to a deductivist scheme. Going back to the street-map analogy, it’s easy to deduce where roads must go because of the map even if they don’t! Yet it can never be used as a rival of systematic theology. Christ was not only crucified and raised; he was “crucified for our sins and was raised for our justification.” Doctrine arises from the drama, indicating the significance of God’s acts in creation, redemption, and consummation.

Resources for biblical theology

Besides the stand-bys, like Geerhardus Vos and Herman Ridderbos, some good introductory resources for biblical theology are on offer these days: especially from the pens of people like Graeme Goldsworthy, Bruce Waltke, and M. G. Kline.