The counter to Systematic Theology is to focus primarily on Biblical Studies and largely within a framework that is often called a Redemptive-Historical hermeneutic.
This view approaches Scripture in terms of a context, a story or narrative that is in a process of development. Themes are accentuated and they both decipher and define how doctrines function as revealed within the narrative and thus (necessarily) in different situations today.
There is a dynamism at work that allows doctrines to be defined in a more fluid fashion that can sometimes 'seem' contradictory depending on how they are paired or contrasted with other truths.
The complexities of the relationship between the Old and New Testament present a perfect example of this dynamic. The nature of the relationship is such that it cannot be defined in a systematic coherent way in which absolute propositional statements can be made. Typically in a systematics framework such statements are then utilised to predicate and deduce further concepts which interact with the text, sometimes to the detriment and even negation of what the text is actually saying.
If these systematising tendencies in any way restrict the full import of the text, which they (by necessity) are wont to do, then the resulting corpus of doctrine is on the one hand guilty of speculation and on the other it represents something less than a complete picture of what Scripture purports to teach.
While attempting to create a holistic structure the systematician actually falls into a necessary reductionism. The parts are reduced to make them integrate within the whole.
The Systematician counters by arguing that Scripture cannot be dealt with in terms of atomistic contextualised definitions. In other words terms and concepts can't be broken down based on specific instances. Doing so, treats Scripture in a reductionist fashion akin to the scientific method. Science breaks down the complex into the simple in order to explain it. Scripture has One Author and thus a unified message (it is argued) and thus must necessarily present a form of coherence.
The Redemptive-Historical approach of contextualising content runs the risk of reductionism by focusing on author, setting and missing the overall unified message which always points to Christ.
Indeed this can happen and certainly does in many modern Evangelical approaches to Scripture. It's a valid concern but is not applicable or attributable to those with a high and Christocentric doctrine of Scripture.
The Systematician may argue for Christocentricity but in placing coherence as the central criterion for validity, it becomes clear that logic and not Christ is the central organising principle. There are those who would equate the two but in doing so they clearly will (ultimately) abandon any form of orthodox historical Christology and Trinitarianism. Maybe that's what they wish to call for but in doing so they need to be clear.
Redemptive-Historical hermeneutics when done properly places Christ and the centre of all Scripture. Christ is the binding principle as opposed to any systemic coherentism or holism. Christ is the resolution of all purported contradictions, dynamisms, dialectics and dualities. And yet resolution must be understood parallel to the Incarnation. The resolution in human terms and categories will likely result in mystery.
What will often seem to be incongruent or contradictory can rest intellectually (and otherwise) in the Person of Christ. He is the Revelation of God and thus faith in Him affords us the ability to set aside such dilemmas. In addition the duality of His Person (as it were) allows for a dynamic function in the realm of theology. He is the example, the very hermeneutic that in defiance of empirically referenced and dependent logic allows us to formulate an apprehension or understanding of God's communication to us in Scripture.
In fact grasping the wonder and centrality of the Incarnation we should expect the very nature of Revelation to exhibit the same irresolvable dialectic tensions. Just as we cannot hope to comprehend the Incarnation, we should not even attempt to reconcile the Eschatology revealed in the categorically temporal nature of theology. Our task as believers is to submit to and accept what God has revealed.
Focusing on themes and context with this approach is not reductionism. In fact in seeing Christ as the centre of the narrative, the focus of the whole story we can find a unity. In truth the narrative, the text comes alive and is enriched as we begin to see the typology is present everywhere. The Scriptures are miraculous in their coherence to be sure but the degree of wonder and awe is magnified when we suddenly see that Christ is literally on every page. The book cannot be the work of men. There is no book like it in all creation nor will there ever be. It is a divine supernatural book.
There is another type of Biblical Theology that focuses on context, atomises the text and breaks down even the themes into reductionist and thus dissectible parts. This is but another form of scientific hermeneutic. Rooted in unbelief, the centrality of Christ is eliminated. This variety is commonly found in theologically liberal circles and has made serious inroads into Evangelicalism. While these authors will occasion exhibit some insight and extract some helpful bits from the text, their overall approach is defective and must be rejected. Without a proper doctrine of Scripture, they're bound to lose their way.
Beware any 'scholar' who posits a system in which an educated unbeliever possessing the right 'academic' toolkit is able to understand and explain the correct meaning of Scripture. This view, all too common among Evangelical scholars reduces the Bible to a natural book, one that is something less than a supernaturally produced work of Spirit-wrought inspiration that has also been preserved by the God's Providence.
Approaching Scripture without inspiration and Divine Authorship in mind will focus excessively on human authors and their own development rather than the fact that as prophets, they are indeed human and in context. Their humanity and character shine through but it is the Holy Spirit who is the author.
The Holy Spirit doesn't point to a system. He points to a person, the Incarnate Risen King, the Messiah Christ Jesus.
Christ is the coherence, the interpreter and discerner of all parts of Scripture. All logical tangles, open ends and irreconcilable concepts find their solution (again as it were) in Him.
It is telling the Divine Author chose not to communicate in terms of an encyclopaedia but in narratives, epistles and apocalyptic vision. This alone reveals a great deal about the contextual and historical nature of how revelation is to be comprehended and interacted with.
This approach is not suggesting doctrines are to be left atomised. This is yet another form of Nominalism dominating theology. And yet no one is really suggesting that. What modern scholarship does is it produces uncertainty with regard to the integrity of text, the nature of its message and certainly its objectivity in terms of truth and sustainability as a timeless and enduring standard.
Contrary to this view we have tremendous certainty, but the nature of our knowledge is limited by the text itself. Different epistles will say different things about salvation, atonement, Baptism. We take those teachings as absolute. But we focus on the themes and contexts always tethered to Christ and His Kingdom.
What we don't do is start trying to 'fill in' and develop these ideas and bring them into an integrated whole... beyond what the text allows. If we're left with uncertainties and seeming contradictions, then that's what we're left with. The so-called Analogy of Scripture is a useful tool but must be limited to certain categories. If it's used to cancel out what portions of the text say, then it becomes Ockham's Razor in the hands of a theologian.
Often the problem lies in a failure to leave what is said... in its context, pertinent to the occasion. It's when scholars try to bind it all together into a coherent system that 'problem texts' arise. Why are they problems? Because they're not fitting in with the whole. 'Problem' means they have to be contorted somehow. The problem isn't the text. The problem is the system and even more importantly... the method.
We have knowledge to look forward to. The eschatological reality of the mind of Christ is a wonder worth waiting for. What we have now is but the firstfruits, a foretaste of the glory that awaits us. Let us be context to dwell in a state of informed ignorance. Such a reality makes us all the more dependent on God and His Word.