I saved this little quote in my draft folder for some time, and when I pulled it out again I forgot where I got it. It sounded like John Frame, and I did a Google Books search for it fully expecting to see Frame’s Doctrine of the Word of God come up.
But no, it was Vos. Interesting.
Read and learn.
The difference between biblical and systematic theology is not that “one would be more closely bound to the Scriptures than the other. In this they are wholly alike. Nor does the difference lie in this, that the one transforms the Biblical material, whereas the other would leave it unmodified. Both equally make the truth deposited in the Bible undergo a transformation: but the difference arises from the fact that the principles by which the transformation is effected differ. In Biblical Theology the principle is one of historical, in Systematic it is one of logical construction. Biblical Theology draws a line of development. Systematic Theology draws a circle. Still, it should be remembered that on the line of historical progress there is at several points already a beginning of correlation among elements of truth in which the beginnings of the systematizing process can be discerned.”
Geerhardus Vos, Biblical Theology: Old and New Testaments (Carlisle, PA: Banner of Truth, 1975 [Orig. Eerdmans, 1948]), 15–16.