I'm committed to blog through Grudem, but I have at least toyed with writing a shadow biblical theology alongside my reviews of him. I'm doubtful I can keep it up because it's not a priority and I don't know if anyone would be interested in publishing it. But I was flowing this morning, so here is my shadow introduction:
Theology is the study of God. Anyone who has an opinion about God is a theologian, but some study God more extensively and can bring countless voices from the past to bear on the subject. Systematic theology the organization of Christian belief into an overall system according to some organizing principle. You can also present theology from a historical perspective, how it has developed over time, historical theology.
Biblical theology focuses on the theology in the Bible. Most Christian traditions look to the Bible as the starting point for thinking about God and derive the key content of theology from the Bible. To be sure, they can process what they find there in different ways, but the Bible is still usually the starting point. It is possible to have a philosophical theology that is so oriented around contemporary categories that the Bible is largely peripheral, but such an approach will surely tend to be rather nominally Christian from a historic standpoint.
At a point in history when we are more aware of how to read the biblical books in context than ever before, biblical theology has frequently become a collection of the individual theologies of the individual authors or bodies of literature in the Bible--Pauline theology, deuteronomistic theology, etc. Then perhaps some token collection of common denominators may appear at the end.
This situation, in effect, is a logical consequence of the Protestant drive not to let any vantage point beyond the books of the Bible themselves be the fulcrum from which the teaching of Scripture is integrated. This perspective can lead, on the one hand, to a denial that such extra-biblical mechanisms are actually in play. On the other hand, it can lead to a purely philosophical basis for theology that is not concerned about historic Christian traditions.
However, it is my contention that if we are to consider historic Christian positions as valid, we will not only have to put our faith in a genuine progress of understanding within the pages of Scripture but also in the developing understanding of the New Testament within the first few centuries of the church. Whether we realize it or not, we integrate the parts of Scripture from certain fulcrum points in the Bible, understood in a certain way. Because we have to pinpoint these center points from the outside of the Bible looking in (after all, the New Testament books themselves largely don't reference each other), the identification of such fulcrum points is an extra-biblical task to a significant degree.
In the pages that follow, I want to sketch out a systematic biblical theology that listens to the individual theologies of individual authors and bodies of literature but that is organized from the standpoint of what we might call "consensus Christianity," the commonly agreed, orthodox perspectives of Christians throughout the centuries. Since I am in the end Protestant, I hope you will also allow me to do just a little constructive theology, critique and synthesis of traditional Christianity in the light of our contemporary situation.
Inevitably, the best way to apprehend what I am saying here is by observing individual examples. The result would be an orthodox organization of Christian understanding formulated out of the materials of Scripture, in dialog with contemporary concerns and issues. This is the task of this book.