Turretin tackles a question first broached by the medieval Scholastics: is theology theoretical or practical? From our vantage point, the answer seems obvious. Theology must be practical. It must result in faith and obedience. It must bear fruit. The great problem in our day, we think, is that so much of our theological discourse has become theoretical–speculative, esoteric, good for nothing but puffing up smart guys with big brains. But Turretin argues that theology cannot be simply one or the other.

Partly for my doctoral study and partly for my own interest and edification, I’m trying to read through Francis Turretin’s Institutes of Elenctic Theology in 2014 (more likely in 2014-2015).  I’ve read sections of Turretin before, but never the whole thing. So far, I’m going slow and loving it—the careful distinctions, the scholastic approach, the compact prose, the dense prolegomena. I can say without exaggeration that every Reformed pastor with a book budget should have these three volumes on his shelf. Turretin is more relevant and more influential than you think.

Early in the first volume, Turretin tackles a question first broached by the medieval Scholastics: is theology theoretical or practical? From our vantage point, the answer seems obvious. Theology must be practical. It must result in faith and obedience. It must bear fruit. The great problem in our day, we think, is that so much of our theological discourse has become theoretical–speculative, esoteric, good for nothing but puffing up smart guys with big brains.

But Turretin argues that theology cannot be simply one or the other. True theology is “mixed,” partly theoretical and partly practical (1:20-23).

We can understand the practical side of the equation. The mysteries of the faith “are impulsive to operation.” They are meant to incite us to love and worship. “A practical system is that which does not consist in the knowledge of a thing alone, but in its very nature and by itself goes forth into practice and has operation for its object.” Right doctrine counts for nothing if it does not sink into our hearts and find expression in our lives. Theology is chiefly practical.

But it is also theoretical. This is not a pejorative term for Turretin. Rather, “A theoretical system is that which is occupied in contemplation alone and has no other object than knowledge.” Here Turretin is affirming that we have something to learn from the Thomist emphasis on the beatific vision. Knowing the truth, beholding the truth, and reveling in the truth are objects in and of themselves (John 17:13; Jer. 31:34). A sermon without application can still be a biblical sermon if it causes us to see the glory of God in the face of Christ.

Turretin feared that the Socinians and Remonstrants were keen to make theology exclusively practical so as to minimize the doctrines of the Trinity and the incarnation and to pave the way for a common religion of good deeds whereby everyone could be saved. By contrast, Turretin insisted that knowledge of God and worship of God could not be separated, just like knowing what is right and doing what is right must be held together. Theology is theoretical in so far as it points us to God as the chief end in all our knowing and delighting, even as we must insist that this “beholding” produce a “becoming” more and more into the image of Christ.

Kevin DeYoung has been the Senior Pastor at University Reformed Church (RCA) in East Lansing, Michigan since 2004. Kevin blogs at the Gospel Coalition; this article is reprinted with his permission.