Creation Speaks: Natural Law, Psalm 19, and the Recovery of Moral Theology for Evangelical Political Thought
June 10, 2026
June 10, 2026
Abstract: Andrew T. Walker defines natural law based on Psalm 19, arguing that it is the objective moral order established by God and woven into the fabric of creation. Though sin has impaired our ability and willingness to conform to God’s design, and though God’s revelation in Scripture is necessary for salvation and Christian obedience, God has made known certain moral norms to all people, and these norms help provide the context for why the gospel is needed. Understanding natural law, which has historically been taken for granted in the Reformed tradition, helps the church to properly embrace God’s moral order and to bear witness to him amid an unbelieving world.
Within certain corners of the evangelical and Reformed world, natural law has sometimes been viewed with suspicion—as though appealing to nature and reason undermines the authority of Scripture, or as though it represents a concession to Roman Catholic moral theology that downplays human sinfulness and hesitates to speak from the Bible in public life. The suspicion is understandable, at times, but it is historically uninformed.
For most of the Christian tradition—including the Reformed tradition—natural law was simply taken for granted as a moral theory. It was situated within the doctrine of creation, and it was assumed in the works of Luther, Calvin, the Reformed Orthodox, and the broader tradition of Reformed Scholasticism.11 .John T. McNeill, “Natural Law in the Teaching of the Reformers,” The Journal of Religion 26, no. 3 (1946): 168–82. Even where the term itself has fallen out of favor in contemporary Protestant thought, the concept persists under alternative labels: creation order, general revelation, creation ethic. The conceptual substance remains even when the vocabulary changes, mostly because Christianity will, inexorably, rely upon its tenets if it hopes to engage secular society.
The real problem today is not that natural law is misguided or unbiblical. The problem is that it has largely disappeared from our theological vocabulary. And when it disappears, several consequences result. Our arguments in the public square become weaker, which goes a long way toward explaining why evangelicals were caught flat-footed in the marriage debates. Our doctrine of creation becomes thinner. In its outward-facing interactions, the church can begin to look as though it inhabits its own moral ghetto, as though Christian ethical claims are believable only by faith and untethered to reality as it actually is. Worse still, we end up with a truncated understanding of how God reveals himself and a narrow account of Scripture’s sufficiency—one that leaves us scrambling for Bible verses when confronted with questions like IVF that the Bible does not directly address.
But natural law is not a threat to Scripture. Properly understood, it is one of Scripture’s own teachings. And the place to begin making that case is Psalm 19.
Before turning to our anchor text in Psalm 19, a working definition is in order: Natural law is the objective moral order established by God and woven into the fabric of creation. It reveals the orderly design of creation, the goods toward which human beings are ordered, and the moral norms that distinguish right from wrong. Theologically, this moral order reflects the wisdom and character of the Creator. Anthropologically, human beings—made in the image of God—possess rational faculties that allow us to recognize aspects of this moral order through the exercise of reason.
A qualification is immediately necessary. Because of sin, our perception of this order is darkened. Human beings suppress the truth. But our rational capacities are not destroyed. Historic Reformed theology holds that the intellect is wounded, not extinguished. Through God’s common grace, people remain capable of recognizing basic moral truths—which is why societies can still distinguish between good and evil, make laws, condemn injustice (think of the Nuremberg trials), and pursue the common good. Sinful humanity suppresses the truth in unrighteousness, not in total ignorance. Scripture portrays humanity’s opposition to the natural law not primarily as a knowledge problem but as a problem of the will.
In short, creation speaks morally because creation was designed morally. And as rational creatures, we are endowed with capacities to know basic truths about the moral order.
Psalm 19 is often read as a beautiful poem about nature and Scripture. But it is doing something much deeper. It provides a map of how moral knowledge works. David structures the psalm in three movements: creation (vv. 1–6), in which the moral order is revealed; covenant (vv. 7–10), in which the moral law is specified in inscripturated form; and conscience (vv. 11–14), in which the moral law is internalized. The psalm moves from cosmic revelation to covenantal legal revelation to personal application. Or we could categorize God’s revelation as visual (creation), verbal (law-code), and visceral (conscience). All told, Psalm 19 offers a remarkably sophisticated moral theology, and we should marvel at how the Bible speaks about the way God reveals himself and makes us capable of receiving that revelation. Psalm 19 shows us how God reveals moral order in creation, clarifies it in his Word, confronts the human heart, and how visual, verbal, and visceral revelation all harmonize as expressions of God’s moral law.
David begins with creation. “The heavens declare the glory of God, and the sky above proclaims his handiwork” (Ps. 19:1). The psalmist describes creation as a kind of universal proclamation. But there is a fascinating paradox: verse 3 says, “There is no speech, nor are there words.” Creation speaks—but without words. It communicates through what we might call visual revelation. And note the language of verse 2: “Day to day pours forth speech, and night to night reveals knowledge.” Creation is not whispering. It is pouring forth speech—an abundance of revelation. Consider the manifold ways that even sinful human beings marvel at creation and act intelligibly within it.
Some evangelicals today, out of good intentions, are hesitant to say that natural revelation actually conveys moral knowledge. They want to protect God’s special revelation and uphold the doctrine of sin. But David has no such reticence. He explicitly says that night after night reveals knowledge. He is speaking declaratively and descriptively about what is true objectively. This revelation is universal. No language or cultural barrier prevents it. It reaches everyone by virtue of their humanity participating in God’s order. It is what C.S. Lewis called the “Tao” in The Abolition of Man—a cosmic moral reality pervades human existence.
This is what theologians call general revelation—the idea that creation itself testifies to the Creator’s moral law. Genesis 1–2, together with the Noahic Covenant, grounds and then reasserts the normative intelligibility of creation toward its proper ends. Human beings thrive when they live in harmony with their natural state as created beings, utilizing their abilities effectively for their intended purposes. A fish, for example, is most free in water rather than on land. And the same is true for human beings: the propensity to push against the created limits of our nature may feel like freedom, but in time those limits have a way of reimposing themselves—often at great cost to those who believed the elimination of limits was liberation, when in fact it leads to bondage.
Paul echoes this idea of creational witness in Romans 1: “What can be known about God is plain to humanity, because God has shown it to them. His invisible attributes—his eternal power and divine nature—have been clearly perceived in the things that have been made” (vv. 19–20). And Paul’s point is not how little people know. It is how much they know. Humanity is “without excuse” (v. 20). The problem is not ignorance. The problem is suppression. Sinners suppress the truth in unrighteousness (v. 18). They push it down, but the truth keeps resurfacing—like trying to hold a beach ball underwater. We see this today in our society’s growing unease with the consequences of transgender ideology and the fallout that comes from the dissolution of the family.
Scripture does not teach that nature fails in its task. Scripture does indeed testify to the fallenness of sinners, but the problem is not that nature fails to reveal. The failure lies with the creature. We refuse what is plainly visible and morally binding in what has been revealed.
Psalm 19 is not merely praising nature’s beauty. It describes moral design embedded in reality. The sun follows its course. The heavens operate with regularity and purpose. Creation is ordered. And the same God who orders the heavens orders human life. Creation is therefore normatively thick—not morally neutral; universally intelligible in that believer and unbeliever alike can access it; and ontologically grounded in that morality corresponds to reality. What Christians insist is true is not merely true for Christians but for everyone. This is the basic insight of natural law: moral norms track with creational design.
At verse 7 of Psalm 19, the psalm suddenly shifts. The name of God changes from Elohim, the God of creation, to YHWH, the covenant Lord. The focus moves from the heavens to the Torah. The implication is clear: if creation provides moral order, the written law—special revelation—provides moral clarity. Creation shows us that a moral structure exists. Scripture specifies what obedience looks like.
David describes the law with six attributes: perfect, sure, right, pure, clean, and true. These words describe more than rules. They describe the moral character of divine revelation. If the first movement of Psalm 19 concerns visual revelation, this second movement concerns God’s verbal revelation. And crucially, special revelation does not contradict creation or general revelation. It presupposes both and clarifies them.
The Decalogue (or Ten Commandments) illustrates this principle. Many of the commandments assume creational realities. The prohibition of murder presupposes the image of God as established in Genesis 1 and 9. The norms of marriage—complementarity, exclusivity, permanency—point back to Genesis 2. Sabbath observance points back to creation itself. The written law does not invent morality. It codifies what is present in creation. It was not permissible to murder before the sixth commandment was given; the sixth commandment merely makes explicit what the creation order already implies.
Psalm 19 therefore corrects two common errors. The first is natural law without Scripture, which leads to vagueness and distortion—Aristotle, after all, used natural law reasoning to defend slavery. The second is Scripture detached from creation, which risks portraying moral law as arbitrary, as if God imposed rules without reference to human nature. But Scripture repeatedly teaches that God’s written law reflects the same wisdom that structured creation. The law is not arbitrary. It is the verbal expression of the wisdom that made the world.
In the final movement, the psalm turns inward—it turns toward the visceral, felt reality of the moral witness located within our interior recesses, the conscience. The focus shifts from the cosmos and the law code to the human heart. “Who can discern his errors? Declare me innocent from hidden faults” (v. 12). David recognizes that the law confronts the inner life. He speaks of hidden faults, presumptuous sins, the words of the mouth, and the meditation of the heart. Here we encounter the moral law applied to the conscience.
Paul describes this reality in Romans 2:15: Gentile non-believers “show that the work of the law is written on their hearts, while their conscience also bears witness.” Conscience does not create moral law. It registers moral law. It is a moral awareness system. And so Psalm 19 gives us a remarkably coherent framework: creation reveals that a moral order exists; Scripture clarifies that order and names our duties before God; and conscience, coinciding with both creation and the written law, applies moral knowledge to the human heart.
Beneath this framework lies a deeper theological truth. God created human beings in his image with rational faculties capable of perceiving the moral structure of the world. Reason is therefore not autonomous—it is a creaturely faculty dependent on God’s design and subordinate to his revelation. But subordinate to Scripture does not mean contradictory. Faith and reason come from the same divine source. Scripture clarifies and corrects what reason perceives and misperceives in creation. When reason functions properly, it recognizes the moral truths embedded in creation. Scripture then authoritatively articulates those truths. Faith and reason are not rivals. Special revelation and general revelation are not rivals. They are gifts of God, designed to work together and emanating from one divine source.
This is precisely where natural law fits. Natural law simply describes how human beings, using reason, can recognize aspects of the moral order woven into creation. God is not schizophrenic. There is not one moral code for non-Christians and another for Christians. There is one moral order known through three distinct modes: creation, the law code, and conscience. The God who authored Scripture is the same God who authored creation. Truth discovered by sound reason and truth revealed in Scripture cannot ultimately conflict, because both proceed from the same divine Author. Which means that when Christians speak about morality, we are not proposing something strange or unnatural. We are not imposing an alien ethic on the world. We are telling the world what is true about itself.
And there’s a warning for when we depart from the natural law: All secular and progressive moralities are not only violations of Scripture, but they are also absurd and irrational. Paul says that persistent rejection of the moral law leads individuals to become “futile in their thinking” (Rom. 1:21) and to social destruction (Rom. 1:22–31).
In contrast, our moral claims are not alien to the world. They are fitted to the world we actually live in. Christian morality is morality. Christian morality is reality. Period.
The major point is this simply this: Psalm 19 refuses both natural law without Scripture and Scripture severed from creation.
What difference does this make for the church?
First, natural law provides a shared moral grammar. When Christians argue for justice, human dignity, or the sanctity of life, we are not introducing foreign ideas into public life. We are appealing to truths embedded in creation itself.
Second, natural law helps us articulate the moral logic of Scripture. Behind the prohibition of murder lies a deeper moral reality—human life is a basic good, grounded in the image of God. Natural law helps us see and articulate the underlying structure often embedded within Scripture’s commands.
Third, natural law exposes cultural contradictions. A society that loudly proclaims fairness and equality while allowing biological males to dominate female athletic competitions, for example, has abandoned the very principles it claims to defend. When our culture says we may take the life of a child eighteen weeks inside the womb but that a child eighteen weeks outside the womb deserves protection, we can name that for what it is: an absurd, irrational conclusion. Life is life at every stage. Natural law exposes bad arguments.
Fourth, natural law deepens discipleship. When we teach ethics, we should not merely present a list of prohibitions. We should teach the goodness of God’s design. Sexual ethics is not merely a series of negations; it is about learning to steward a good gift within the design God created.
Fifth, natural law reminds us that joy and human flourishing follow from aligning ourselves with the moral order. God did not design his law as an arbitrary burden. He designed it for our joy. Obedience to God is not the suppression of our humanity—it is its fulfillment.
Sixth, natural law undergirds civil society. Even fallen societies establish laws, punish injustice, form families, pursue knowledge, and build civilizations, because creation itself presses toward order.
Seventh—and I save this for last deliberately—natural law may persuade unbelievers, but it may not. The fundamental human problem is not merely intellectual; it is volitional. Sinful wills resist moral truth. If someone has not arrived at their moral conclusions by way of reason, they will not be reasoned out of them. This means our use of natural law is not primarily apologetical.
It is first catechetical. Natural law trains Christians to recognize the moral order of God’s world and to understand why God’s commands are good. It forms moral imagination. It teaches believers to see reality rightly. And in doing so, it prepares us to speak truthfully and confidently in a confused age.
Natural law does not replace the gospel, but it prepares the ground for it.22 .Andrew T. Walker, “The Gospel and the Natural Law,” December 8, 2020, First Things, https://firstthings.com/the-gospel-and-the-natural-law/. As theologian David VanDrunen writes, “If a contemporary world tempted to nihilism is to hear the gospel—really to hear it—it needs to understand that the world actually has a purpose and that the evil and suffering surrounding us are not the way things are supposed to be. There is nothing more important for the church than proclaiming the good news of salvation for the world in Jesus Christ. Far from undermining the message, natural law provides the scaffold.”33 .David VanDrunen, “Natural Law for Reformed Theology: A Proposal for Contemporary Reappropriation,” Journal of Reformed Theology 9, no. 2 (2015): 129, https://doi.org/10.1163/15697312-00902018.
Natural law helps supply the framework that makes the majesty of the gospel intelligible to a broken world. It helps people recognize that something in the world is wrong. And once they see the moral mess of the world around them and their own moral debt as a violation against the law of God that saddles the conscience with guilt, the gospel becomes intelligible. The gospel announces that the Creator has come to redeem his creation.
And here we arrive at the climax. The moral order of creation is not upheld by an abstract principle. It is upheld by a person. Christ is the one through whom all things were made, in whom all things hold together, and who upholds the universe by the word of his power. The moral order of the world is not an impersonal system. It is sustained by the living Word of God.
Natural law can establish that a moral order exists. But it cannot explain why that order will ultimately prevail, why it is worth defending at personal cost, or why human beings—broken as we are—keep trying to give our lives a purpose. For that, you need the news that the Author of the moral order has entered history, has borne the accumulated weight of human moral failure, has assuaged divine wrath, and has walked out of a tomb a living, breathing human being. The resurrection is thus not an accessory to natural law. It is the reason for Christian moral confidence, because it tells us that creation is not evacuated of substance or purpose.
C.S. Lewis once called the moral structure of the universe the “Tao.” But later in life, he reflected on that concept and asked a remarkable question: “Is not the Tao the Word Himself—considered from a particular point of view?”44 .Letter to Clyde S. Kilby, January 11, 1961, quoted in Michael L. Peterson, C.S. Lewis and the Christian Worldview (Oxford University Press, 2020), 74. And Lewis is exactly right. The natural law is not an abstraction. It is the imprint of Christ upon creation.
When we speak about natural law, we are not talking about something foreign to the Christian faith. We are talking about the moral structure God built into the world. Psalm 19 shows us that creation declares it, Scripture clarifies it, and conscience registers it. And ultimately, Christ fulfills it. Christians should not be embarrassed to speak of natural law—we should put it in its proper place. The natural law is not a summons to de-center the Bible in our public pronouncements, nor is it an invitation to a Christless moral law—it is an entry point that leads people to the question of who the source of that moral law is. We should want the world to recognize moral truth because the world and its creatures were designed to do so. And when we speak about morality in public life, we are not introducing something strange. We are pointing people back to the order that God placed in his creation from the beginning.
This essay will be published in a forthcoming volume by the author. Crossway has granted permission for it to be published in this format.