Natural Theology Within the Covenant of Nature
John Owen follows Bullinger in a twofold Word of God, the book of nature and the book of Scripture. He maintains, therefore, a natural theology, and like his predecessors on continental Europe, e.g. Francis Turretin, he understands said natural theology under two distinct circumstances. Of prelapsarian natural theology, he writes, “Mankind was created pure and placed with undefiled nature under the laws of creation. In that situation, true theology was also natural and God-given.” Alluding to a relationship between natural theology and covenant, he says, “Adam’s light… was both God-given and capable of increase and strengthening by following the precepts of the divine will, and by prayerful meditation upon the works of the Creator.” Speaking more to the kind of theology Adam possessed prior to the fall, “That which derives its nature from first principles is not inaptly styled ‘necessary’ or ‘natural.’” Though, Owen certainly maintains this theology should be credited to God since God must ultimately disclose Himself and His will through the object of natural theology.
Owen moves to make an explicit connection between the covenant of nature or works and Adam’s natural theology when he says:
Indeed, obedience by demonstrating the power of the covenant, must have been willing and intelligent to conform with the theology which we have outlined above [sic]. Adam recognized both his own duty and the promised reward by the efficacy of this theology. The covenant was coeval with mankind, but voluntary obedience was a means of signing and sealing it on Adam’s part. The proposed reward of obedience consisted in nothing more or less than the secure and eternal enjoyment of God.
Unquestionable is it that Owen understood there to be a natural theology inextricably connected with the covenant of nature. He does say, after all, “all true theology is based on some form of divine covenant.” Adam’s natural theology was the very means by which he would obey the natural covenant between himself and his Creator. In Owen, as in Turretin, the covenant of works provides the natural if not ontological context for prelapsarian natural theology.
The Insufficiency of Natural Theology
We must now say something about Owen’s view of the insufficiency of natural theology. The insufficiency of natural theology for salvation is affirmed by all the orthodox. However, Owen makes clear the correspondence of natural theology to works of the law—
All such knowledge, however derailed it might become, could only serve the purposes of the first covenant, the covenant of works. From the day on which that covenant was made void by sin, its efficacy has gone and the best that it can do is to work an outward obedience by the terror of threatened punishment.
Quoting Augustine, he says:
A man might “… keep the commandments through fear of punishment and not through any love to righteousness; what he does externally, he does not perform in his heart. Therefore, internally, he is guilty of sin, however innocent he might deem himself to be…”
Owen saw significant interplay between the covenant of works, man’s obedience to it, and natural theology. Natural theology, therefore, emerges in Turretin and Owen’s thinking as most proper to the covenant of works. But what about Owen’s understanding of the present, postlapsarian use of natural theology? It seemed it could be used, perhaps, as a means of common grace, encouraging, as it were, a civil obedience. It is, moreover, assumed and studied in every legal jurisdiction throughout the world, to one extent or another. However, natural theology cannot be correctly appropriate by those who remain in the broken covenant of works, dead in their sin. Speaking of its place in fallen man, he remarks:
Our verdict upon the first, that remnant inner light, must be this—like everything pertaining to fallen man, it is sinful and flawed. Similarly, its teaching is imperfect and it remains, as I remarked earlier, confined within the limits of the law and contains nothing germane to the saving knowledge of Christ. As the sinful minds of fallen men are replete with darkness and blindness, they must, of necessity, be also faulty in their manner of perceiving divine truths; and so the spiritual efficiency of such remnant light must be fatally limited.
Natural theology, in the final analysis, is not of much use to the fallen man beyond that of mere civil obedience and jurisprudence. It will take higher revelation, together with spiritual illumination in order for man to react to natural theology appropriately.
The Renewal and Use of Natural Theology Under the Covenant of Grace
Owen’s method of arrangement leads him from a lengthy discourse on natural theology under total depravity to the renewal of a true theology following the fall of man. Beginning this section, he writes:
Now we must turn our attention to the phase of theological development which succeeded [natural theology] and took its place. This is not to say that natural theology ceased entirely to exist, or that this new phase (on which we are now embarking) simply replaced it bodily. Rather, the strands of the two combine; remnants of the former surviving the inroads of corruption and combining with the latter and, so, progressing onwards through several noteworthy stages which must be examined.
The “phase” mentioned by Owen should be understood to represent a covenantal shift, “In a word, this new phase of theology consisted of the teachings and promises of the covenant.” As mentioned, however, Owen doesn understand natural theology to be absolutely nor entirely displaced by this covenant of grace. Natural theology, being now the object of renewed man, will be used as an instrumental means of understanding and maturing in this new covenant. Muller writes, “In very much the same vein (of Turretin), Owen can indicate that ‘the inbred principles of natural light, or first necessary dictates of our intellectual, rational nature’ provide a ‘rule unto our apprehension’ of all things, even of divine revelation.”
Owen, thus, represents a full-fledged Reformed orthodoxy on this matter. There are others, such as Johann Heinrich Alsted, Stephen Charnock, Herman Witsius, and Petrus Van Mastricht. Yet, any differences between them would be mostly accidental and not relevant to the overall point of the present essay. Owen clearly understands theology in genera within the context of covenant. Natural theology is germane to the covenant of works. And while it remains, the theology of the covenant of grace makes use of natural theology, but moves far beyond it to Trinity, the incarnation, the atonement, the church, etc. This would, in large part, remain the orthodox judgment on the matter up to the 20th century.
 John Owen, Biblical Theology, (Morgan: Soli Deo Gloria Publications, 1996), 20.
 Muller, PRRD, vol. 1, 301.