Petrus van Mastricht (1630–1706) has increasingly attracted scholarly attention for his massive Theoretical-Practical Theology and especially for his famous fourfold method of exposition, doctrine, polemics, and practice. Modern discussions often present this fourfold structure as Mastricht’s distinctive contribution to Reformed orthodoxy. While this observation is certainly correct, it risks mistaking the visible architecture of Mastricht’s theology for its deeper organizing principle. The more fundamental question concerns why Mastricht adopted this method and what theological vision governs it.

The answer emerges in the Prolegomena of the Theoretical-Practical Theology. There Mastricht repeatedly insists that theology is neither mere speculation nor the simple accumulation of doctrinal propositions. Rather, theology is “the doctrine of living for God through Christ.“¹ This definition functions not as a concluding summary but as the governing principle of the entire theological enterprise. Theology begins with divine revelation, proceeds through doctrinal understanding, and culminates in holy living. Every aspect of Mastricht’s method serves this end.

This article argues that Mastricht’s theological methodology is fundamentally teleological. Exegesis, systematic arrangement, polemical defense, and practical application are not independent tasks but successive moments within a single movement from divine revelation to godly life. His fourfold method arises from his definition of theology itself. Consequently, Mastricht’s method cannot be understood properly apart from his conviction that theology exists to direct human life toward God through Christ.

Theology as the Doctrine of Living for God Through Christ

The methodological center of Mastricht’s theology appears in his definition of theology itself. He writes: “This theoretical-practical Christian theology is nothing less than the doctrine of living for God through Christ.“² This definition deserves greater attention than it has often received. Much scholarship begins with Mastricht’s pedagogical structure. Mastricht himself begins with theology’s object and end.

Several features of this definition are significant. First, theology is doctrine. Theology consists of divinely revealed truth communicated by God and received through faith. Theology is not generated through autonomous human inquiry. Rather, it originates in divine revelation and therefore bears the authority of God himself.³

Second, theology concerns living. Theology is not primarily ordered toward speculative contemplation but toward the formation of human life. According to Mastricht, theology differs from every other discipline because it alone directs the whole of human existence toward its proper end. Medicine concerns bodily health, politics concerns civic well-being, economics concerns household management, but theology directs all human actions toward God.⁴

Third, theology concerns living for God. Human life finds its proper goal only in God as its highest and ultimate end. Without this orientation, every human pursuit ultimately loses its direction. Theology therefore functions as the discipline that orders all subordinate ends toward the supreme end of God’s glory.⁵

Finally, this life is lived through Christ. Here Mastricht distinguishes Christian theology from every merely natural theology. Human beings do not live for God apart from Christ’s mediatorial work, the gift of the Spirit, union with Christ, and participation in Christ’s life. Theology is therefore fundamentally Christological in its structure and orientation.⁶

This definition establishes the controlling logic of Mastricht’s method. If theology is the doctrine of living for God through Christ, then every theological activity must contribute to that end.

The Biblical Foundation of Method

One of the most striking features of the Prolegomena is that Mastricht grounds even his discussion of theological method in biblical exegesis. Rather than beginning with philosophical reflection on the nature of science or method, he begins with Scripture itself.

His discussion emerges from 1 Timothy 6:2–3, where Paul commands Timothy both to teach and to exhort. From this text Mastricht derives a twofold task: “He should teach, that is, he should inform the intellect … He should exhort, that is, by moving the will, so that what the intellect perceives is carried over into practice.“⁷ This passage reveals the basic movement that governs Mastricht’s theology. Teaching informs the intellect through the exposition of truth and the refutation of error. Exhortation moves the will so that truth becomes embodied in life. Knowledge and practice therefore belong together within a single theological act.

Significantly, Mastricht describes this practical movement as “the chief end of theology and its highest apex.“⁸ Theology reaches its completion not when doctrine is understood but when doctrine is enacted. Theological understanding finds its proper fulfillment in obedience. The entire structure of Mastricht’s method emerges from this exegetical foundation. Scripture reveals truth. Truth informs the intellect. The informed intellect directs the will. The renewed will produces godly living. Theology therefore possesses an inherently teleological character from beginning to end.

Why Theology Must Be Systematic

Mastricht’s defense of theological method represents one of the most important and underappreciated sections of the Prolegomena. Against any suggestion that systematic theology imposes an artificial structure upon Scripture, Mastricht argues that theological method arises from the nature of divine revelation.

His central claim is straightforward. Because Scripture constitutes an ordered revelation from an orderly God, theology must be arranged according to a fitting method. He writes that “theology must be taught according to a certain method,” and that theory and practice must “always walk in step together.“⁹

Mastricht offers several arguments for this conclusion. God himself is a God of order and therefore desires all things, especially sacred matters, to be conducted in an orderly manner.¹⁰ Scripture repeatedly displays methodical organization through structures such as the Decalogue, the Lord’s Prayer, Hebrews 6:1–2, and the doctrinal arrangement found throughout the Pauline epistles.¹¹ Furthermore, the covenant itself is described as “ordered in every respect” (2 Sam. 23:5), a description Mastricht extends to the scriptural witness that records God’s covenantal dealings.¹²

Perhaps most importantly, Mastricht observes that theological topics are dispersed throughout the biblical canon. The doctrines of God, Christ, salvation, the church, and the last things are not confined to single passages or books. They appear throughout Scripture in various forms and contexts. Consequently, theologians must gather, arrange, and synthesize this material into coherent doctrinal structures.

Systematic theology therefore does not compete with exegesis. Rather, it extends exegesis. Exegesis discovers biblical teaching; systematic theology gathers and orders that teaching according to its intrinsic unity. Theological method thus becomes an act of obedience to Scripture’s own nature as a coherent divine revelation.

Christ as the Source and Teacher of Theology

Another neglected dimension of Mastricht’s methodology is its profoundly Christological character. For Mastricht, theology belongs uniquely to Christ because Christ alone is the infallible teacher of the church. He argues that only the theology that comes from Christ is worthy of being taught among Christians. Christ descended from the bosom of the Father, perfectly knows the Father, reveals the way of worship, and possesses the power of eternal life that theology seeks.¹³ Consequently, Christian theology originates neither in autonomous reason nor in merely human authority.

This emphasis is particularly important because it places revelation at the center of theological method. Theology is not fundamentally the result of human investigation. Rather, it is received from Christ through Scripture. Mastricht repeatedly contrasts divine revelation with fallen human reason, insisting that the genuine principles of theology cannot be derived from nature alone or attained through human industry apart from God’s self-disclosure.¹⁴

This Christological emphasis also explains Mastricht’s understanding of theological authority. Theology possesses certainty because its source is not human opinion but divine revelation. Its truth rests upon the faithfulness of God and the authority of Christ himself.

The Integration of Theory and Practice

The most distinctive feature of Mastricht’s methodology is his refusal to separate theory from practice. He insists: “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.“¹⁵ This statement should not be interpreted as a simple division between doctrinal and practical sections. Rather, Mastricht means that every theological locus possesses both theoretical and practical dimensions.

This conviction appears repeatedly throughout the Prolegomena. Christian theology is “theoretical-practical theology.“¹⁶ Theology consists of “the knowledge of the truth that is according to godliness” (Titus 1:1).¹⁷ Following the church fathers and figures such as Lactantius, Mastricht argues that wisdom and religion belong together. God must first be known, but that knowledge necessarily issues in worship and obedience.¹⁸

Theology therefore cannot terminate in intellectual comprehension alone. Every doctrine demands corresponding acts of faith, worship, repentance, obedience, and devotion. Knowledge that does not lead to godliness remains incomplete. Theological understanding reaches its proper end only when it shapes the life of the believer.

Spiritual Formation and the Acquisition of Theology

Mastricht’s doctrine of theological method reaches beyond pedagogy and hermeneutics into spiritual formation. The acquisition of theology requires not only intellectual effort but also spiritual preparation. He argues that theology must first be sought from its divine author through prayer, illumination, and dependence upon the Holy Spirit.¹⁹ Students must cultivate humility, godliness, and reverence before God.²⁰ They must devote themselves to Scripture, meditation, discussion, and practical obedience.²¹ Pride, vain curiosity, fleshly wisdom, and sinful desires must be rejected because they hinder theological understanding.²²

This aspect of Mastricht’s method reveals a profound epistemological conviction. Theology cannot be reduced to information transfer. Genuine theological understanding requires moral and spiritual transformation. The theologian is not merely an observer of divine truth but a participant in the reality that theology describes. Theological knowledge and holiness therefore belong together. The person who would know God rightly must seek God faithfully.

Conclusion

Petrus van Mastricht’s theological methodology cannot be reduced to his famous fourfold structure of exegesis, doctrine, polemics, and practice. That structure emerges from a deeper conviction concerning the nature and purpose of theology itself. Theology is “the doctrine of living for God through Christ.” This definition governs the entirety of Mastricht’s theological vision.

Exegesis provides the foundation of theology because God has revealed himself in Scripture. Systematic theology gathers and orders scriptural truth because divine revelation possesses an intrinsic coherence. Polemical theology defends that truth against distortion because the church must preserve the gospel. Practical theology applies that truth because theology reaches its fulfillment only in godly living.

The result is a theological method characterized by movement. Revelation leads to understanding. Understanding leads to conviction. Conviction leads to worship and obedience. Theology therefore exists neither for speculation nor for intellectual mastery but for communion with God through Christ.

At its deepest level, Mastricht’s method is not merely a pedagogical strategy. It is a theological account of how divine truth forms human life. Theology begins with God’s self-revelation and ends with believers living for God through Christ. Everything else in Mastricht’s method serves that single end.

References

1. Petrus van Mastricht, Theoretical-Practical Theology, vol. 1, Prolegomena, ed. Joel R. Beeke, trans. Todd M. Rester (Grand Rapids: Reformation Heritage Books, 2018), 98.
2. Mastricht, Theoretical-Practical Theology, 98.
3. Mastricht, Theoretical-Practical Theology, 101–2.
4. Mastricht, Theoretical-Practical Theology, 99–100.
5. Mastricht, Theoretical-Practical Theology, 100.
6. Mastricht, Theoretical-Practical Theology, 102–3.
7. Mastricht, Theoretical-Practical Theology, 64–65.
8. Mastricht, Theoretical-Practical Theology, 65.
9. Mastricht, Theoretical-Practical Theology, 67.
10. Mastricht, Theoretical-Practical Theology, 68–69.
11. Mastricht, Theoretical-Practical Theology, 67–68.
12. Mastricht, Theoretical-Practical Theology, 67.
13. Mastricht, Theoretical-Practical Theology, 73–74.
14. Mastricht, Theoretical-Practical Theology, 101–2.
15. Mastricht, Theoretical-Practical Theology, 67.
16. Mastricht, Theoretical-Practical Theology, 73.
17. Mastricht, Theoretical-Practical Theology, 78–79.
18. Mastricht, Theoretical-Practical Theology, 78–79.
19. Mastricht, Theoretical-Practical Theology, 92–93.
20. Mastricht, Theoretical-Practical Theology, 93.
21. Mastricht, Theoretical-Practical Theology, 94.
22. Mastricht, Theoretical-Practical Theology, 93–94.