How One Book Changed My Life (Part 3)

Michael Spangler

Previously I discussed how Petrus van Mastricht, in the recently translated prolegomena of his Theoretical-Practical Theology, taught me to submit to the Word of God (part 1), and how he gave me a biblical and balanced view of the use of reason in theology (part 2). In this third and final part I discuss what was the most life-changing for me, and I trust for many who will read it: Mastricht's definition of theology itself as "the doctrine of living for God through Christ" (98).

Theology is for living.

 In defining theology Mastricht takes his start from Paul's words in 1 Timothy 6:3, that doctrine is "according to godliness" (63, 98), and from there builds his definition, arguing that everything in Scripture points to the end of living for God (Rom. 6:11; 2 Cor. 5:15; Rom. 14:7-8; Col. 3:3-4; Phil. 1:20-21; p. 98), and moreover, as faith without works is dead (James 2:17), and knowledge without love (1 Cor. 8:1; 13:1-2), so is doctrine without practice. Theology is not, therefore, merely theoretical. Nor is it mixed, partly theoretical and partly practical, as if some doctrines should be practically applied and others not. Indeed, though Mastricht's title, Theoretical-Practical Theology, describes his method--every chapter treats theory (exegesis, dogmatics, and elenctics), then practice--it does not describe theology itself, which he insists is entirely and preeminently practical (106-107). In theology, theory is necessary, but its goal is practice; or as he puts it in his book on preaching, "the practice of piety" is "the soul of a sermon" (4). And "piety," is nothing less than a life in union with the Lord Jesus Christ (11).

Mastricht is sure that no Christian will differ from his definition of theology, if not in words, at least in substance (104). Such a definition is manifestly biblical, and such a theology as it defines meets the manifest need of our world, and of our churches: not talk, but power (1 Cor. 4:20), not a dead faith (James 2:17), but a faith working through love (Gal. 5:6).

But though I now agree that Mastricht's definition is profoundly biblical and necessary, I admit that I used to be unconvinced. I feared that such a practical definition unduly removed from theology its status as a science, that it focused on practical precision at the expense of wholesome truth, and that in preaching it encouraged legalistic application instead of warm preaching of Christ and him crucified.

Mastricht's teaching and example have proven that all my fears were false. He explains that theology is not less than a science, it is more (100, 104-105), and that because among all disciplines it has the highest goal, living for God, it therefore has the highest excellence and dignity (104). Moreover, he never sacrifices truth to practice. Practice is indeed the goal of the entire work, but the explanation and defense of the truth is so vital for that end that it takes up the majority of its pages: each chapter's express treatment of practice is only one part of four, and the work's final sections on morality and piety (forthcoming volume 7) together make up less than one tenth of the whole (see p. 52, n. 8). Moreover, his application, though heart-searching, is not distracted by vexed questions of casuistry: it is brief, pithy, biblical, and broadly applicable.

And regarding my fears about preaching, though it is perhaps true that some "practical" preachers are legalistic and frigid, I found that Mastricht certainly was not. His love for God and Christ fills the work with a delightful aroma, and as I showed in my first article, the Practical Part of each chapter should warm the heart of any true believer. So now after reading this volume, far from fearing practical preaching, I have embraced it, seeking as Mastricht taught me to make the practice of piety the soul of all my sermons.

Living is for God, through Christ.

But there is one reason above all that kept Mastricht, and should keep those who follow him in practical theology, from any hint of cold precisionism. Theology is not merely about living: it is about living for God, through Christ. Its chief end is God's glory, and the great means it seeks to that end is our union and communion with God (103), which comes only through the Mediator, Jesus Christ (102).

Thus if I could name just one defining feature of Mastricht's Theoretical-Practical Theology, it is that it is full of the glory of God. God's name, his Son, his Spirit, his perfections, his Word, and his salvation are the subject of every page, and Mastricht urges every reader to embrace them with faith and love. Thus though the book brought certain needed changes in my life, in this way it met my greatest need of all: to know the only true God, and Jesus Christ whom he has sent (John 17:3), and therefore to live, through Christ, for God (Rom. 6:11). My prayer is that for all who read it, it would do the same.

Michael Spangler is a minister in the Orthodox Presbyterian Church and assists with the editing of Mastricht's Theoretical-Practical Theology. He lives with his wife and children in Greensboro, NC.