Some Thoughts on the Definition of Biblical Theology

In recent years biblical theology has become increasingly popular in Christian circles. That is not to say that “the truths of the Bible” or “biblical doctrines” were unpopular and are now becoming popular, or that there has been any particular revival in the church, but rather that a certain way of doing theology is becoming more popular in pulpits, in the Christian blogosphere, and in the academy. Perhaps because of its recent growth into the limelight, many people seem confused about the definition of biblical theology, and this confusion muddies theological discussion. The cause of this is a tendency to define biblical theology in terms of its results and findings instead of its methods.

Carl Trueman recently wrote a four part series on the relationship between systematic and biblical theology at the Mortification of Spin blog (here, here, here, and here). Overall, I think this is an excellent series on the issue he’s discussing. In his third post, discussing biblical theology, he moved away from one definition of biblical theology (“to set forth the ideas and beliefs of the biblical writers themselves, being always sensitive to the particular historical context of specific books of the Bible”) and toward another, which he attributes to Geerhardus Vos (“[the] modern redemptive-historical method of interpretation [takes] the historical nature of scripture seriously, but orthodox in seeing the whole Bible as containing one, consistent story which has a unity”). However, defining biblical theology as the latter would be a mistake. Trueman seems to take a balanced understanding of the definition of biblical theology between these two extremes, but his discussion focuses on the weaknesses of doing biblical theology under the latter description.

In his Biblical Theology: Old and New Testaments, Geerhardus Vos defined biblical theology as “that branch of exegetical theology which deals with the process of the self-revelation of God deposited in the Bible.” That is, biblical theology is the “History of Special Revelation.” Now Vos does go on to talk about a centralized storyline of the Bible describing the process of redemption, but this does not constitute the definition of biblical theology. Any good orthodox biblical theology is going to find unified storylines in the Bible, but any honest practitioner of biblical theology is going to struggle to determine a single central theme to the Bible. A complete biblical theology has to deal with multiple storylines, not just a single story.

At its basic level, then, the raison d’être of biblical theology is to describe what theology or doctrine is revealed at different historical points in the Bible’s development. As defined in John MacArthur and Richard Mayhue’s Biblical Doctrine, “Biblical theology is characterized by the organization of Scripture thematically by biblical chronology or biblical author with respect to the progressive revelation of the Bible.”

So biblical theology should be defined as something like the “History of Special Revelation.” The defining concern of biblical theology is to determine what doctrine or theology is being taught historically within a portion of the Bible. The end result, and certainly a hopeful purpose of biblical theology, is to produce a relatively unified description of how theology was revealed over time through the formation of the canon. But this is not the only possible purpose of biblical theology; future synthesis into systematic theology can and should be a purpose of biblical theology. Indeed, this is a natural outgrowth of determining historical theological revelation. Maintaining that purpose as a priority alleviates many of the concerns raised in the Trueman blog series.

But a more troubling confusion of the definition of biblical theology is part of a recent interview of Ligon Duncan on Nancy Guthrie’s TGC podcast. Full disclosure: I do not subscribe to Covenant theology as laid out by Duncan, so I do have a bias. About the 17:00 mark of the interview he defines biblical theology as the history of redemption. I think this begs the question: how does one trace the history of redemption? What source can one use to do so? Is it not this progressive revelation made in the Bible? And so by asking the question of the history of redemption, one makes an assumption: the key theological theme of the Bible is redemption.

Now redemption is absolutely a key theme in the Bible. But biblical theology is supposed to be the kind of method you could use to tell you what the central themes of the Bible are. So if one defines biblical theology in terms of one of its potential results (that is, that the Bible is primarily about redemption), then one has made a huge theological assumption, and in turn limited the potential outcomes from your biblical theological study. Indeed, a number of other very conservative theologians (Michael Vlach and Thomas Schreiner would be two) actually argue using biblical theology that the Kingdom of God is the central theme of the Bible. What stops them from defining biblical theology as the study of the progress of the Kingdom of God in history?

The problem here came from defining biblical theology in terms of the conclusions made by its practitioners. Biblical theology should instead be defined in terms of its method: studying the historical development of theology within the formation of the canon, studying the history of special revelation, studying what the Bible teaches in specific books and authors. This is not the sum total of theological activity by any means. It forms a sufficient ground to define the field of biblical theology without writing off people from other theological traditions.