D.A. Carson gives a helpful big summary of biblical theology in the Dictionary of the Later New Testament and its Developments. I read and marked it up on Logos. I recommend it.
D.A. Carson gives a helpful small summary of biblical theology—or at least the way people use the term—in his book Christ and Culture Revisited:
“Biblical theology” has become a highly disputed expression.
- Some use it to refer to the theology of individual biblical books or corpora (e.g., the theology of Matthew, the theology of Paul).
- Others use it to refer to the theology of the Bible when the Bible is studied diachronically, over against systematic theology, which tends to be organized topically, synchronically.
As subsets of this latter category there are two further refinements.
- When some hear the expression “biblical theology,” they think of how various themes can be traced right through the Bible, or through large parts of it. These themes constitute the ligaments that hold the canon together: rest, temple, sacrifice, priesthood, kingdom, covenant, and so forth.
- Others reflect on what I have called “the great turning points in redemptive history.” (44-45, bullets supplied for easy reading)