I recently got a copy of Petrus Van Mastricht’s newly translated Theoretical-Practical Theology: Prolegomena (vol. 1). I agree with Michael Horton: this is a remarkable gem! Van Mastricht was a Dutch Reformed theologian who was quite influential in his day and beyond. Not only is his work solidly theological and biblical, it is also very practical, as you can tell from the title. It is true that sometimes Reformed theology is taught in a dry manner with little or no application. However, I very much agree with those like Van Mastricht who say that theology is eminently practical and applicable. Below are a few quotes of his that show how theology and practice go hand in hand. It’s also worth mentioning that Van Mastricht often referred to Paul’s words to Titus in 1:1, where the apostle mentions the knowledge of the truth which is according to godliness (NASB).
…Theology must be taught according to a certain method, and it must be the kind of method in which theory and practice always walk in step together. In fact, they must walk together in such a way that theory precedes and practice follows in every one of theology’s articles. (p. 67)
We approve, out of all methods, the one that the apostle not only commends in this text to Timothy, when he wishes that theological matters first be taught and then admonished, that thereby practice be perpetually joined to theory, but also employs everywhere throughout his epistles, especially those he wrote to the Romans, Ephesians, Hebrews, and others. By this method, I say again, practice should be joined to theory, not only in the whole corpus of theology, in such a way that the first place is especially reserved for the things that must be believed and the second for the things that must be done, but also that in each member of theology, practice should walk in step with theory in a continuous agreement. (p. 69)
He [Paul] also commands that what can be taught should also be applied, adn that doctrine should be according to godliness, that is, theoretical-practical. He prohibits Timothy from teaching in any other way. (p. 73)
Christian theology unites theory with practice, and is ‘a knowledge of truth that is according to godliness’ (Titus 1:1). (p. 79).
Indeed, the study of theology, to the extent that it is true theology, is not sufficient, unless… it is earnestly devoted to practical theology and to practice. (p. 95)
In fact, here’s how Van Mastrich defines Christian theology:
…Christian theology is best defined as the doctrine of living for God through Christ. (p. 66)
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