The historico-theological situation of natural theology within the Protestant Reformed corpus rightly requires some relationship between the natural knowledge of God, the covenant of works, and the covenant of grace. This relationship differs depending upon the nature of either covenant, and what each one either assumes or promises to do. Sometimes, within the historical body of literature on the subject at hand, this relationship is brought out explicitly, while at others it is more or less implicit, yet nevertheless present. The following essay will attempt to demonstrate a correspondence between natural theology on the one hand, and the prelapsarian (before fall) covenant of works and postlapsarian (after fall) covenant of grace on the other. In addition to an historical demonstration of this relationship, a la historical theology, this essay will provide substantial philosophical and exegetical argumentation in service of the thesis above—that the historical Protestant Reformed corpus rightly makes the connection between natural theological knowledge and God’s covenants.
The productivity of debate centered around the aforementioned issues depends on definitions. There are three main terms in question throughout this essay: natural theology, covenant of works, and covenant of grace. I will flesh out a working definition to be assumed throughout the remainder of this essay for each of these terms, and any other term requiring definition will be defined upon its employment.
By natural theology I do not mean natural revelation. In this essay, natural theology refers to the innate and acquired knowledge of God and His will derived from natural revelation. Natural theology (theologia naturalis), as Richard Muller puts it, is “the knowledge of God that is available to reason through the revelation of God in the natural order.” Moreover, this natural theology is both innate and acquired which means the present essay will count references to knowledge of God through conscience, on the heart, etc., as references to innate natural theology in connection with the cognitio Dei insita, or the innate knowledge of God.
By the covenant of works I do not mean either the Abrahamic or Mosaic covenants which may be considered covenants whos’ formal bases are obedience. I only mean the covenant imposed by God upon the first man, Adam. God made Adam such that he might comply with all its stipulations, namely to “tend and keep” the garden as a prototypal priest (Gen. 2:15), to partake of garden fruit, chiefly that which was borne from the tree of life (Gen. 2:16), and to abstain from eating of the tree of the knowledge of good and evil (Gen. 2:17). Associated with this covenant were blessings for obedience and curses for disobedience. The former consisted of continued life and eventual, albeit hypothetical, eschatological consummation; the latter of death (Gen. 2:17; 3:3).
I do not anticipate much disagreement with this definition. The goal of this essay does not require its author to navigate the more controversial aspects of the covenant of works, i.e. the nature of Adam’s hypothetical eschatology or the republication debate with respect to the Mosaic covenant. It also does not demand a defence of the nature of the Abrahamic covenant as a covenant of works—a position I hold, yet one that remains irrelevant to the ensuing discourse. The focus in this essay, with reference to the covenant of works, is the state of man’s knowledge of theology prior to the fall in relationship to the assumptions made in the imposition of such a covenant upon the prelapsarian human race.
By covenant of grace I mean the gracious covenant God revealed in Genesis 3:15 with the promised “Seed.” This covenant was established in the blood of Christ upon the completion of His cruciform work (Matt. 26:28; Jn. 19:30). The focus in this article will be upon the covenant blessings of regeneration and renewal, the effect of which is a repentant frame of mind and an improvement in man’s ability to receive and discern the things of God revealed not only in nature but also in Scripture.
Mapping Out Our Course
The underlying purpose of this essay is to examine various motives which might have led the low to high Reformed orthodox toward a retainment of natural theology in their systematic and dogmatic work. Because of the nature of the current project, the methodological order will not follow traditional systematic or dogmatic arrangement. The reasons for this will hopefully become obvious if they have not already. However, there are a few housekeeping items to consider before we proceed—
First, the present essay will presuppose the truth of the Christian faith. The project at hand is an historical-theological survey of what past theologians of the Reformed orthodox tradition believed about the interplay between natural theology and covenant theology. Moreover, it also contains a philosophical and theological justification for their belief in said relationship. Because of this, we will not set out to prove the validity of natural theology only to proceed in relating the covenants to it. Rather, the extent to which natural theology becomes a necessary article within the Reformed system of theology will be evaluated in terms of how related it is to God’s covenants, especially the covenant of works God made with Adam prior to the fall (cf. Gen. 2). Thus, rather than offering natural reasons for natural theology (there are several we could give), this particular essay will offer explicitly theological reasons for the retainment of natural theology within the body of Reformed confessional orthodoxy. The end-product of this essay will, hopefully, be a persuasive case for retaining natural theology on reason of Reformed theological convictions characteristic of its orthodoxy. Rather than mere historical or rational justifications for natural theology, this essay will venture to ground the conviction of natural theology not only in historical, but also in biblical-theological data.
Second, conventional wisdom tells us to argue natural theology from Romans 1:19, 21; 2:12-16; and other places such as Psalm 19. However, to be evinced in this essay is a deeper, more comprehensive reason for natural theology revealed in Scripture. Romans 1, 2, and Psalm 19 are not to be read in a vacuum, but must be understood within the broader covenantal, or biblical-theological backdrop in front of which they appear. There are more fundamental explanations behind those texts that will confirm the historical exegesis from a biblical-theological standpoint.
Third, an assumption made in this essay is that the covenant of works and the covenant of grace have actual ontic status (the have being, exist, etc) outside the pages of Scripture, yet are not altogether independent of Scripture. In other words, just as the incarnate Christ has a historically real presence on earth distinct from the pages of Scripture, but nevertheless inspirationally and infallibly revealed therein, so too do God’s covenants have real historical existence which have affected—if not determined—history up to the present. The covenants are infallibly revealed in the pages of Scripture, yet they are not limited in their ontology to the pages of Scripture. They are real historical things made known respectively through general and special revelation; the covenant of works through general and special revelation, the covenant of grace through special revelation alone. The mode by which either covenant is revealed will play a large role in the remainder of this essay.
 Richard Muller, Dictionary of Latin and Greek Theological Terms, (Grand Rapids: Baker Academic, 2017), 362.
 Meredith Kline, Kingdom Prologue, (Eugene: Wipf & Stock, 2006), 87ff.