Bernard Lonergan talks about eight "functional specialties" in the work of theology: research (within theology and biblical studies: textual criticism, more or less), interpretation, history, dialectics, foundations, doctrines, systematics, and communication. He has a wonderful phrase: the former specializations are more essential, the latter more excellent. That is to say, one cannot interpret a text without the antecedent work of textual criticism, thus making textual criticism more essential; yet textual criticism is hardly an end on to itself, but rather creates the conditions for interpretation, which transcends textual criticism (in the strict, literal, sense, of going beyond--transcending--the limits of what textual criticism aims to do; the latter specialties are more "excellent" in the empirical sense of building upon and moving beyond the former specialties). Thus the work of a textual criticism can eventually, and perhaps indirectly, contribute to the work of a systematic theologian, yet that does not mean that the textual critic is doing systematic theology. In fact, the textual critic need not think about anything but her or his own work, and can in fact treat it as an end on to itself; it retains its own autonomy, which need and indeed should not be compromised for the needs of the latter specialties.
Now, the obvious objection to the above is as follows: "Well, I'm not a theologian, so talking about functional specialties in the work of theology is irrelevant." In response I would of course acknowledge that Lonergan worked out this eight-fold schema within the context of Catholic theology; yet, I would also note the empirical reality that I, who am not a Catholic theologian, find this schema quite useful. Why do I find it nonetheless useful? Well, because I think that it can be translated into a basic outline for the relationship among various levels of thought within not just theology and biblical studies and beyond. Let us consider how this might work by moving through the specialties, with specific focus upon biblical studies.
Research--as noted, within theology and biblical studies more or less the work of textual criticism.
Interpretation--the work of understanding what the person or persons who produced the texts with which we work aimed to communicate.
History--the work of inferring from texts (and other material) previously interpreted what was happening in the past (or, as Lonergan puts it, "what was going forward," i.e. what was changing over time, with no value judgment implied by the word "forward").
Dialectic--the work of inferring from "what was going forward" the conflicts that were driving the forward movement. Classic examples of such work include the Marxist tendency to foreground class conflict, or the feminist tendency to foreground gendered conflict. Of course, one might find multiple conflicts driving history forward, that can be studied in terms of class, gender, race, more traditional intellectual history: all of which might well be at play.
Foundations--the work of taking a side on these conflicts. The Marxist does not simply say that class conflict is a significant factor in the forward movement of history but rather takes a side in that conflict, namely with the subordinated classes; the feminist takes a side in gendered conflict, namely with women's struggle for equality and justice.
Doctrines--from the work of taking a side in conflicts one begins to develop formal "doctrines." Examples might include the Marxist doctrines of false consciousness or hegemony or the feminist doctrines of patriarchy and androcentrism.
Systematics--once a body of "doctrines" exists one begins to bring them into relationship with each other. The Marxist considers how false consciousness relates to hegemony and other Marxist doctrines, the feminist how patriarchy and androcentrism relate to each other and other feminist doctrines.
Communications--one a systematic understanding of the world begins to emerge there is an effort to make this intelligible in the specific time and place in which one operates. The Marxist thus considers how false consciousness and hegemony are operating here and now, the feminist how patriarchy and androcentrism.
I intentionally used Marxism and feminism in my above examples, in order to demonstrate how this eight-fold schema, although articulated by Lonergan in terms of the Catholic thought in which he was immersed, can aid in the process of organizing different levels of investigation operating within different traditions (and the Marxist and feminist traditions are precisely that, viz. traditions: a term here used in the purely empirical sense of referring to a cluster of discourses joined by shared history and common concern). For the biblical scholar the salient point is that the arch-conservative can in principle reach exactly the same conclusions vis-à-vis research, interpretation, history, and dialectics as the most radical Marxist-feminist. They will begin to diverge sharply with the work of foundations and thereafter, with the arch-conservative usually sounding more and more like this as the discussion proceeds.
Something like the above schema allows us to determine what sort of argumentation is relevant for what discussions. This is why I in fact think that countering anti-LGBT Christians on the level of biblical or Pauline interpretation is the wrong move. It is better to engage them at the level of foundations through communications. Foundations: by what warrant have you decided that you agree with (your interpretation of) Paul on this matter? Doctrines: how has agreement with (your interpretation of) Paul led to a particular formulation of the doctrine of marriage? Systematics: how do you relate that doctrine of marriage to other key Christian doctrines, such as grace? Communication: how do you convince the rest of us that we should agree with your foundational, doctrinal, and systematic views on the matter? Because if the anti-LGBT Christian cannot answer those questions then frankly it is irrelevant what Paul said on the matter.