1. Exegesis: analysis of the biblical texts in their historical and literary contexts.
2. Biblical Theology: situating exegesis in wider context of each body of literature (e.g. theology of the Pentateuch or Pauline Corpus and then OT or NT Theologies respectively). Importantly, Biblical Theology looks at the issues that the biblical authors raise in their own language and on their own terms without importing foreign ideas or issues.
3. Systematic Theology: the act of synthesizing key motifs and ideas as they relate to the mosaic of Christian belief done in dialogue with Philosophy, Scripture, and Tradition.
Importantly, Systematic Theology is the end process of exegesis and Biblical Theology. In short, exegesis and Biblical Theology determines Systematic Theology rather than the other way around. That means that there is a genuine risk that Systematic Theology will have to modify its findings based on the results of good exegesis and a sound Biblical Theology. But there are a cohort of Reformed Theologians who are calling into question the validity or results of Biblical Theology precisely because (I suspect) that it is deterimental to their Systematic Theology. Let me give three examples:
2. Guy Waters. Waters' book Justification and the New Perspective (2004) presents a good and accessible survey of the debate about Paul and justification, he scores a few good points on Wright, Dunn, and Sanders at certain places, but overall the book is written with an uncharitable rhetoric that is unfortunate (e.g. he calls Wright a "trojan horse to the church"). What I found somewhat disconcerting about the book is when Waters says this about J.P. Gabler: "Warfield, Vos, and John Murray were agreed that the former [Biblical Theology] was properly the handmaiden to the latter [Systematic Theology]. These three men were good students of the historical-critical thought and had remembered how biblical theology in the tradition of J.P. Gabler had decimated systematic theology, both as an ordering principle of biblical data and as a force within the church" (p. 202). The problem here is what Waters attributes to Gabler is patently false. Gabler's concern was to stop Dogmatic Theology imposing itself upon the biblical texts and distorting the texts, espeically when the results of Theology kept changing. He called for the development of a separate discipline of Biblical Theology that would allow the biblical texts to speak on their own terms on their own issues and without preempting results. What is important to remember is that Gabler wanted the results to feed into Systematic Theology and into the life of the Church. Gabler writes: "Thus, as soon as all these things have been properly observed and carefully arranged, at last a clear sacred Scripture will be selected with scarcely any doubtful readings, made up of passages which are appropriate to the Christian religion of all times. The passages will show with unambiguous words the form of faith that is truly divine; the dicta classica [standard collection of proof texts] properly so called, which can then be laid out as the fundamental basis for a more subtle dogmatic scrutiny. For only from these methods can those certain and undoubted universal ideas be singled out, those ideas which alone are useful in dogmatic theology . . . And finally, unless we want to follow uncertain arguments, we must so build only upon these firmly established foundations of biblical theology, a dogmatic theology adapted to our own times" (English trans. in SJT 33.2 , pp. 143-44). Does this sound like a guy who is trying to prevent theology from being a force in the church? And if you don't believe my reading of Gabler, here is D.A. Carson's description: "Gabler charged that dogmatic theology is too far removed from Scripture, constantly changing and perpetually disputed. Biblical theology, by which Gabler seems to mean a largely inductive study of the biblical text, has much more likely hood of gaining widespread agreement among learned, godly and cautious theologians. The fruit of such study may then serve as the basis on which dogmatic theology may be constructed" (D.A. Carson, "New Testament Theology," DLNTD, p. 796). Carson goes on to note that many followed the first part of Gabler's proposal (inductive study free from doctrinal consideration) but they did not follow him in the second part of feeding the results into the service of dogmatic theology. But Gabler was not against Systematic Theology itself and Gabler was I think correct in his vision of seeing Biblical Theology determining the contours of doctrinal formulations - a point which some Systematicians take exception too!