For dispensational theology to get underway properly there needs to be a methodology which comports with the progress of revelation as recorded in the outworking of the covenants of God in history. This introduces “Biblical Theology”; a tried and true definition of which, as well as an agreed upon methodology, has been elusive, so we must familiarize ourselves with the debate.
The Contribution of Biblical Theology
Taking the usual starting point as J. H. Gabler’s inaugural address at the University of Altdorf (1787), we encounter a strongly rationalist approach to the discipline, which focuses on the scientific character of history. Biblical theology was not concerned with being doctrinal (which was for the dogmaticians). Its area of concern was in the accurate representation of the beliefs of the people who left us these historical religious pieces. For Gabler, the historical outlook of the age from which a passage or book sprang was what needed to be discovered. Biblical theology was for him a purely descriptive subject.
Particularly important for Gabler was the belief that there was no necessary connection between the religion of the Old Testament and that of the New. As history changes so do beliefs and practices (although truth is constant). This means that the truths within the Bible are arrived at by an excavation process, wherein each writing (or writer) is studied and his conceptual contribution analyzed. The evaluation methods were held to produce truth, which could then be utilized by the systematicians. Hence, biblical theology was thought to be an independent historical enterprise, and normative in its own right. Dogmatic (Systematic) theology was a different animal, delivering up normative teachings to the Church. Another way to put the difference is that biblical theology is active and processional while systematics is logical cum organizational.
From the time of Gabler up until nearly cusp of the twentieth century biblical theology and systematic theology were viewed in utter contrast the one to the other. In 1894, at his Installment address as first Professor of Biblical Theology at Princeton Theological Seminary, Geerhardus Vos tried to demonstrate how the two could coexist. Although Herman Bavinck had made a few noteworthy comments, “within the Reformed tradition Vos has no predecessors for his conception of biblical theology.” Vos has been all but ignored by most scholars, but he has done some of the most conspicuously biblical and exegetical work in the whole field. We shall return to him presently.
Biblical Theology Beyond Evangelicalism
Beyond evangelicalism a major step forward was made by Eichrodt in his three volume Theology of the Old Testament. Eichrodt first rejected any scheme that he felt forced dogmatic guardrails around the Old Testament’s story. He believed, in fact, that it “contained very little actual doctrine.” He replaced it with a unifying, or better, a controlling concept – that of “covenant” (berith), principally the Mosaic covenant. This was and remains very influential, although the present leaders in the non-evangelical wing of biblical theology, men like Brevard Childs, have developed new approaches that emphasize the witness of both Testaments. Childs’ Biblical Theology of the Old and New Testaments is an attempt to bring about a resolution of 1. the discrete testimony or “witness” of the Old Testament; 2. the discrete witness of the New Testament; 3. the theological value of the Christian Bible. This seems to us to be a good scheme (although Childs’s lack of strong belief in inspiration infects his work).
 See the survey in Gerhard F. Hasel, “The Relationship Between Biblical Theology and Systematic Theology,” Trinity Journal 5:2 (Fall 1984), 117-125.
 Hasel, 113.
 James Barr, The Concept of Biblical Theology, (Minneapolis: Fortress Press, 1999), 62.
 Hasel, 114.
 Ibid, 115.
 Charles H. H. Scobie, The Ways of Our God: An Approach to Biblical Theology, Grand Rapids: Eerdmans, 2003), 16.
 Richard B Gaffin, Jr., “Systematic Theology and Biblical Theology,” Westminster Theological Journal 38:3 (Sept. 76), 290.
 Geerhardus Vos, “The Idea of Biblical Theology as a Science and as a Theological Discipline,” in Redemptive History and Biblical Interpretation, 23.
 Herman Bavinck, Reformed Dogmatics, 1.82-83.
 Gaffin, 287.
 Walter Eichrodt, Theology of the Old Testament, (Philadelphia: Fortress Press, 1967).
 Barr, The Concept of Biblical Theology, 29.
 Ibid, 30.
 Ibid, 42.
 Brevard S. Childs, Biblical Theology of the Old and New Testaments, (London: SCM Press, 1992).
 Barr, 417.