What is biblical theology?

There are many answers to that question, and just as many approaches to “doing biblical theology.” Recently, friends at the 9Marks e-Journal put out a helpful resource on the subject as it relates to the church: “Biblical Theology: Guardian and Guide for the Church.” And if you keep up on the web, you may come across anything from a blog series on a biblical theology of dessert to a list of resources for understanding the framework of the Bible.

Yet, is there anything out there that simply defines biblical theology for someone whose never heard of it before? What follows is something I wrote up for our church. It expresses my own appreciation for biblical theology and how this discipline can serve non-theologians who may have never heard the term. 

(Disclaimer: “non-theologian” is a misnomer; everyone made in the image of God (that’s everyone) is by nature theological and hence a ‘theologian’ in their own right).

Defining Biblical Theology

Biblical theology can be defined in one of two ways. It can be theology that finds its source in the Bible (as opposed to ‘unbiblical theology’). Or, it can be theology developed over the whole Bible (as opposed to systematic theology, which is organized by topics; or, historical theology, which arises from various people and places in church history).

It is the latter, as a discipline of interpretation, that I want to discuss. Why? Because few things have helped me know or love God more than a clear understanding of a whole-Bible theology, and few things are more important for growing Christians to walk in a manner worthy of the gospel.

How I Stumbled Into Biblical Theology

When I went to seminary I had heard much about theology that should be biblical, but I was less familiar with biblical theology that started in Genesis and gradually proceeded to the New Testament. Imagine my shock when my theology professor began explaining baptism and told the class to turn to Genesis 6.

In a moment of great mental confusion, I remember thinking, “Wait a minute! Baptism is in the New Testament. What are we doing with Noah?” But of course, this professor did the very same thing Peter did in his first epistle (3:20–21). When explaining what baptism meant in the church, Peter turned to the first place “baptism” is found in the Bible—Genesis 6.

This is biblical theology. At least, this is the biblical theology that grapples with individual concepts progressively revealed through the Bible.

To be fair, there are other kinds of whole-Bible theologies. Some of these look synthesize the message of the Bible under one major theme (e.g., God’s kingdom, God’s covenant, or God’s glory). There are also biblical theologies (plural) that look at what how various biblical authors explain concepts like justification, faith, or eschatology. Did I mention that there were various approaches to biblical theology?!? 

For now, let’s zoom-in on biblical theology as a tool for understanding various doctrines in the Bible. This approach is a slow-moving process of watching doctrines develop over time and revelation (i.e., the biblical canon).

With baptism, for example, you can see how Moses’ baptism of Israel at the Red Sea followed the pattern set out in Genesis (cf. 1 Cor 10:2). Likewise, Joshua’s leadership of Israel through the Jordan River also replicated this baptismal pattern (Joshua 3). Then, later in the OT, when the prophets anticipated a future exodus of God’s people, Isaiah used the same imagery: “When you pass through the waters, I will be with you” (43:2). Even Jonah had his own baptismal experience (see Matt 12:40), an event that became pivotal in explaining Jesus’ ultimate baptism—his death on Calvary (Mark 10:38; Luke 12:50).

Now, when someone is baptized in the church, they are united to Christ (Gal 3:27) and to the people of God (1 Cor 12:13). This includes people in the New Testament church, but it also includes the Old Testament saints whose salvation experience also included a kind of baptism.

Long story short, God is uniting a people of faith by means of one common baptismal experience. And while the New Testament teaches how that baptism should be pursued today—i.e., by immersion, for believers, administered by the church, in conjunction with membership—the biblical doctrine of baptism is far larger than a few proof texts. Indeed, baptism is far more than just an obligatory rite; it is the very way in which believers are saved—by faith, they die and rise with Christ (Rom 6:4–5), as water baptism depicts.

The Glorious Utility of Biblical Theology

So you can see how exciting and practical biblical theology is. Not only does it help believers understand the mind of God; it gives a larger framework for rightly understanding biblical doctrines.

In truth, too many Christians base their beliefs on a few isolated proof texts—if they are looking to the Bible at all. What the discipline of biblical theology does is widen the shutter and elongate the exposure, so that our biblical doctrines come on larger prints and with higher-definition. Though it can be misused, biblical theology rightly employed helps Christians see what God is doing in both testaments. Such stereo sound ensures that the doctrines we hold come from the whole counsel of God, not just our favorite passages.

Does it take more work to do biblical theology? Sure, but what could be better than scuba diving in the ocean of God’s Word, rather than wading into few pools of water nearest to us. What biblical theology does for the “non-theologian” is to remind us of the Bible’s unity and to help explain what are the main features of God’s revelation.

Just this morning I picked up the book of Zechariah and found some things in it that utterly perplexed me (read chapters 4–5). Yet, these inspired words are necessary for understanding the doctrine of Christ and last things—to only name a few. Therefore, to have a full grasp of who Christ is and what God is doing in history, I must return to these dark waters until the light of the glory of God reveals what divine truth is there. And from there, I need to expand, detail, or even redraw my theological maps.

Friends, biblical theology is not the only way we do theology, but it is, in my experience, the most exhilarating way to see God in Scripture. While it depends on textual exegesis and must proceed to systematic theology, biblical theology is necessary for ascertaining doctrinal truth, and for delighting in the God who has revealed himself in sixty-six unified books, not just screensaver verses.

Soli Deo Gloria, ds