Why Protestant Christianity Needs a Theology of Natural Law


By David VanDrunen, Westminster Seminary California

Natural law is an idea of perennial importance and controversy in the Western world, and now in other places too. This idea didn’t die in twentieth-century Protestant thought, but it fell on hard times. During the opening decades of the twenty-first century, interest in natural law has suddenly sprung to life again in many Protestant circles. This is an encouraging development—from historical, philosophical, and theological perspective. But it remains controversial.[1]

In this article, I don’t offer a detailed theory of natural law. I simply wish to make a biblical and theological case that Protestants need some account of natural law if they are to make sense of many of their fundamental convictions as heirs of Reformation Christianity.

It is appropriate to begin with a brief comment on what I mean by natural law. In very general terms, natural law is a universally obligatory morality that all people know, or at least can know, simply by being human and living in the kind of world they do. But as a Christian, I want to say more than just this. Natural law, more specifically, is an aspect of God’s natural revelation by which He makes known His basic moral law to all people, not through Scripture but through the world He has made. To be clear, by “natural law” I don’t mean people’s theories about natural law, but the law itself that God reveals through His creation and which thus exists independently of anybody’s theory. People’s theories about natural law are subjective and fallible, and thus always open to debate; God’s natural law is objective and true.

Many people think there is no natural law, and some even find the idea ridiculous. These skeptics have some initially plausible reasons. As they point out, people in different cultures do things differently. There is no universal morality to which all subscribe, at least when we move beyond generalities and examine details. The skeptics also pose some good questions to proponents of natural law: How can understanding the nature of the world really demonstrate how people ought to live? How can someone prove what the natural law is, even if it does exist? When people talk about “natural law,” aren’t they really just reading into nature what they already believe for other reasons and then trying to impose their views on others?

Those aren’t the easiest questions to answer, and it’s not difficult to understand how people can get comfortable with such a skeptical attitude and thus dismiss natural law as an antiquated idea. But as soon as they do, it seems that events arise that force them to reconsider natural law. The Nuremburg trials following World War II offer a good example. Western jurisprudence of the early twentieth century had been quite positivist in character and wary of the notion that civil law is properly grounded in natural law. But then what to do with Nazi officials who had perpetrated atrocities but had done so under the cover of German law and established authority structures? If positive law is the only kind of law, there was no evident basis on which to hold them accountable. All at once, the power and attractiveness of the idea of natural law were evident for all to see.

The notion of human rights, now so prevalent in political discourse, also shows the attractiveness of natural law. For human-rights discourse to make much sense, it needs the ability to make moral judgments across cultures. It needs to claim with conviction that there are certain things that one just should and should not do to other human beings. To say such things is to speak as if there’s a natural law.

After an extended period of widespread denial, scholars have come to recognize that Reformed theology (and other Protestant theologies) widely affirmed the idea of natural law in their early centuries. But influential voices are still wondering whether natural law deserves a place in contemporary Protestant thought. Does recognizing the importance of natural law compromise the importance of the Bible, they ask, and does it underestimate the effect of sin? In the remainder of this essay, I suggest three important reasons why Protestants need a conception of natural law. As I hope to show, they need one not in spite of their doctrines of Scripture and sin, but in order to do justice to these doctrines.

An Objectively Meaningful Natural Order

The first reason Protestants need a conception of natural law is that it enables them to have a coherent and powerful way of affirming that this world is objectively meaningful and purposeful, and that human beings are equipped to discover this meaning and purpose. To put it another way, affirming natural law is to affirm that God made this universe in such a way that there’s a morally appropriate manner for human beings to live within it, and that the moral law revealed in Scripture isn’t arbitrary, but reflects this created reality.

To appreciate this claim, a brief and very simplified description of our historical context may be helpful. In what we sometimes call the pre-modern period, Western culture widely affirmed that the world has objective meaning. Furthermore, this objective meaning was thought to be intelligible to human beings; that is to say, human beings are the kinds of creatures able to perceive and understand the meaning of the world. In this paradigm, truth is primarily something to be discovered, not created. In the so-called modern period, however, focus shifted from the objective world to the subjective human knower. Reason was no longer primarily an instrument for discovering truth in the world but the means for imposing truth upon the world. The world has meaning, in other words, insofar as human beings project meaning onto it. But since moderns believed that all humans shared the same rationality, they thought that as long as they used their rational powers properly, they would all project the same meaning onto the world. Now, in our postmodern world, people not only reject the objective meaningfulness of the world but also question whether reason is universal. For postmoderns, then, each person (or community) imposes its own distinctive meaning onto the world and there are no established criteria for judging whose meaning is better. People are left to construct their own stories and own theories, and each one has his or her own “truth.”

What are Christians to make of this? While they should not identify Christianity with pre-modernism generally, Christians have good reason to affirm the pre-modern belief that the world has objective meaning and is intelligible to human beings. Truth is something to be discovered, not constructed. The idea of natural law is bound up with this conviction: given what we humans are by nature, and given the nature of the world around us, there are appropriate ways for us to live within it. We can’t simply choose to be whatever we want. We are creatures of a certain kind, and this has moral implications.

This is evident already in the early chapters of Genesis. One of the obvious things we see in Genesis 1 is that God created the world, and in doing so He made it with inherent meaning and purpose. God separated one inanimate thing from another—day from night, and water from dry land. God also made animate things according to their kinds—fish, birds, and land animals. He also created human beings, not according to their own kind but in His own image and likeness. In each case, God gave things their own distinct nature. Furthermore, God made each thing with a task to perform that corresponded to its nature. God made the heavenly expanse, and by virtue of being an expanse it was to separate waters from waters (1:7). He made the two great heavenly lights, and by being great heavenly lights they were to rule over day and night and to separate light from darkness (1:16-18). When God created human beings, He made them to rule over other creatures (1:26). This makes perfect sense: as God exercised supreme rule over the world in creating it, so those bearing His likeness were fit to rule in the world under Him. Nothing was arbitrary. Each creature’s commission matched its nature. Each one had meaning and purpose within God’s grand design. And despite the devastation of the fall into sin (Gen 3) and the great flood (Gen 6-7), Genesis 8-9 narrates God’s reestablishment of meaning and purpose in the world. He promises regularity in the cycles of nature (8:22), describes boundaries between humans and beasts (9:2), and affirms that humans remain His image-bearers, with the moral task of ruling in the world by enforcing justice against the violent (9:6).

One of the ways this plays out later in Scripture is in the Old Testament prophets’ treatment of sin. They don’t simply condemn sin as the breaking of an arbitrary divine rule, but as something bizarre, nonsensical, and out of accord with the way things are. Sin flips the order of reality. Consider Amos 6:12: “Do horses run on rocks? Does one plow there with oxen? But you have turned justice into poison and the fruit of righteousness into wormwood.” For Amos, sin is ridiculous. Isaiah also speaks of sin as scrambling the order of nature: “The ox knows its owner, and the donkey its master’s crib, but Israel does not know, my people do not understand” (1:3). “Shall the axe boast over him who hews with it, or the saw magnify itself against him who wields it” (10:15)? “Ah, you who hide deep from the Lord your counsel, whose deeds are in the dark, and who say, ‘Who sees us? Who knows us?’ You turn things upside down! Shall the potter be regarded as the clay, that the thing made should say of its maker, ‘He did not make me;’ or the thing formed say of him who formed it, ‘He has no understanding’” (29:15-16). As these prophets saw it, sin contravenes the nature of things.

On a more positive note, the objective meaningfulness and purpose of the world is also crucial for understanding Scripture’s treatment of wisdom. Just as sin is not simply the breaking of an arbitrary divine rule, but contravening the order of reality, so righteousness is not simply following divine rules, but also living in fruitful and productive ways that fit the world we know. This theme is especially prominent in Proverbs. Living wisely entails a perception of how the world works and how certain kinds of behavior tend to bring harm and other kinds tend to bring blessing. Wise people gain moral insight not by memorizing long lists of rules but through experience, observation, and reflection on life as it transpires around them. Proverbs presumes the existence of a natural moral order that human beings can and ought to understand.

In short, the idea that God has made the world with objective meaning and purpose is a long-standing Christian conviction and an important part of biblical teaching. Human beings themselves have objective, God-given meaning and purpose, rooted in their nature as divine image-bearers. The path God calls human beings to walk isn’t arbitrary or detached from their nature, but corresponds to the way He made them and the broader world. Without some theology of natural law, it is difficult to see how Protestant Christianity can affirm this consistently.

Universal Accountability Before God’s Judgment

The second reason Protestants need a theology of natural law is to enable them to affirm and explain the accountability of all human beings before the just judgment of God. The doctrine of a final judgment is standard fare in classical Protestant theology and in other Christian traditions. A conception of natural law is necessary for explaining how God is just in executing this judgment.

Before considering the reasons for this claim, it may be interesting to reflect on what human beings instinctively think of the notion of a final judgment before the throne of God. There’s something about the doctrine that’s inherently terrifying. The idea that an all-knowing and perfectly holy judge would examine every thought of one’s mind and every passion of one’s heart over an entire lifetime is enough to alarm the most God-fearing person. Yet there’s also something about the doctrine that’s profoundly encouraging and deeply satisfying. It promises that God will set all things right on the final day. In the midst of a broken world filled with intractable injustice, that’s an attractive prospect. Another way to think about this latter point is that sinful human beings still display a remarkable longing for justice. And insofar as they do, they often have to admit that justice simply cannot be done in particular circumstances, given the constraints of this present world. One can sometimes hear this insight emerge after terrible events such as acts of terrorism. Even if the perpetrators can be apprehended, people lament, there’s no way to achieve true justice. No punishment is proportionate to the crime and there’s no way to restore lost limbs and lives to victims. Such situations bring home the realization that if all things are going to be made right, it will have to happen by a supernatural act of divine power.

However sobering the thought of a final judgment may be, Christians confess that it is coming. Scripture not only describes this great day many times but also declares repeatedly that God hates injustice and will bring righteousness to the world. He will right every wrong and hold all evildoers accountable.

This presents another reason why Protestants need a theology of natural law: if God is to administer the final judgment justly, He must hold people accountable for what they know. A just judge should not convict people of deeds they don’t know are wrong, for which they can honestly plead ignorance. A just judge cannot bring charges based on a law that was never promulgated to those in the dock. Thus, we wonder: on what basis will God judge the nations of the world? Protestants might naturally appeal to the divine law revealed in Scripture. God will undoubtedly hold people responsible for breaking this law if they have heard or read it, but a great many people have never been exposed to the Bible. On what basis will God judge them? The existence of a natural law that all people know provides an obvious answer—and it’s also Scripture’s answer.

In the Old Testament, an interesting place to begin exploring God’s universal judgment is the prophetic oracles against Gentile nations. The prophets ordinarily preach to Israel, but all of the major prophets and some of the minor prophets also include prophecies directed toward Israel’s pagan neighbors. Some of these foretell future blessings of salvation, but many are declarations of judgment for their wickedness. Given the issue before us, we wonder on what basis God judges them. When the prophets condemn Israel, they regularly cite its disobedience to the Mosaic law given at Sinai. But the oracles against foreign nations never bring such accusations. The Gentiles didn’t stand before Sinai, and they are not bound by its law. Yet God treats them as morally responsible people who know the difference between good and evil and are accountable for their actions. The opening of Amos offers a good example. Amos begins with six short oracles against Gentile peoples (1:2-2:3) before proceeding to judgments against Judah (2:4-5) and Israel (2:6-16 and following). Only when reaching Judah does Amos accuse the people of rejecting “the law of the LORD” and not keeping “his statutes” (2:4). When he condemns the Gentiles, he doesn’t cite obscure things or matters for which they could claim ignorance, but cites what we might call atrocities or crimes against humanity. They have engaged in slave-trading (1:6), violated treaties (1:9), ripped open pregnant women (1:13), and desecrated dead bodies (2:1). Amos never uses the terminology of “natural law,” but he presumes that all people know that such conduct is reprehensible and deserves punishment.

From a different angle, a striking incident earlier in the Old Testament also testifies to the universal knowledge of right and wrong. Genesis 20 narrates Abraham’s sojourn in the region of Gerar. Concerned that its inhabitants would kill him in order to get his wife Sarah, Abraham tells them that she’s his sister. Abimelech, king of Gerar, proceeds to take Sarah into his house. Warned in a dream that Sarah is really Abraham’s wife, Abimelech calls Abraham into court the next morning and brings charges against him: “What have you done to us? And how have I sinned against you, that you have brought on me and my kingdom a great sin? You have done to me things that ought not to be done” (20:9). This is a remarkable turn of events. The Gentile Abimelech accuses Abraham, God’s covenant partner, of doing what ought not to be done. Abimelech needed special revelation to learn that Sarah was Abraham’s wife, but he didn’t need to be told that that passing off one’s wife as one’s sister is morally abhorrent. Abimelech says, in effect, that there are some things human beings just should not do to one another, no matter where they live or what people they’re from. Abraham had done something that everyone knows is wrong.

The New Testament confirms the Old Testament evidence of a universal judgment of God based on a universal knowledge of right and wrong. In fact, the biblical texts most famously associated with natural law, in Romans 1 and 2, clarify the Old Testament evidence by teaching that this universal knowledge comes by “revelation” and takes the form of “law.”

Paul begins by saying that God’s wrath is being revealed against “men”—not against Jews in particular, but against all people—who suppress the truth in unrighteousness (1:18). How can this be, we wonder, since Gentiles never received God’s law at Sinai? Paul explains, “What can be known about God is plain to them, because God has shown it to them. For his invisible attributes, namely, his eternal power and divine nature, have been clearly perceived, ever since the creation of the world, in the things that have been made. So they are without excuse” (1:19-20). That is, God holds all people morally accountable because He’s made Himself known in the natural created order. Thus, all people in fact know God, although they don’t honor Him (1:21). Paul proceeds to list a host of sins that people fall into (1:22-31) and then declares that they “know God’s decree that those who practice such things deserve to die” (1:32). By virtue of natural revelation, all people know both their basic moral responsibilities before God and that they deserve judgment if they violate them.

Shortly thereafter, Paul confirms the basic principle of justice mentioned at the beginning of this section, that a just judge won’t accuse people on the basis of a law that doesn’t bind them. He writes, “All who have sinned without the [Mosaic] law will also perish without the law, and all who have sinned under the law will be judged by the law” (2:12). Simple and straightforward. But then Paul states, “For it is not the hearers of the law who are righteous before God, but the doers of the law who will be justified” (2:13). This complicates matters. If one has to be a “doer” of the (Mosaic) law in order to be justified, what becomes of the principle that God won’t judge people on the basis of a law they don’t know? Paul answers exactly this question by pointing to the natural law, “For when Gentiles, who do not have the [Mosaic] law, by nature do what the law requires, they are a law to themselves, even though they do not have the law. They show that the work of the law is written on their hearts, while their conscience also bears witness, and their conflicting thoughts accuse or even excuse them on that day when, according to my gospel, God judges the secrets of men by Christ Jesus” (2:14-16). Paul’s point is that a Gentile who performs (or violates) the requirements of the natural law is in the same position before God’s judgment as the Jew who performs (or violates) the requirements of the Mosaic law.

Thus, Romans explains in a more precise way what the Old Testament describes narratively. God holds all people accountable before His judgment, whether they’ve heard the Scriptures or not. And He judges justly even those who haven’t, because He judges them on the basis of the universal natural law which they know, by virtue of being human and living in this world.

Foundation for the Gospel

The final point really gets to the heart of things: Protestant Christianity needs a theology of natural law in order to understand the gospel and to communicate it to the world. In short, natural law makes the gospel coherent. Since there was nothing more central to the Reformation than recovering and proclaiming the good news of salvation, natural law’s connection to the gospel is crucial to consider.

We’ve just reflected on God’s universal judgment and how natural law explains God’s justice in executing it. That is all very important. But the fact is that all of us are sinners, and even the best of us, if we stood before the final judgment on our own with only our own works to show for ourselves, would be in deep trouble. Whatever satisfaction we might enjoy from seeing other wicked people get their comeuppance would be more than muted by the prospect of getting what we ourselves deserve too. As the Reformers passionately proclaimed, we need not only the law but also the gospel, which announces salvation from the judgment of the law through the death and resurrection of Jesus Christ, received by faith alone.

For the Reformers, famously, the “law” describes what God requires from us and the “gospel” describes what God does for us in Christ. But without the law, the gospel makes no sense. The gospel doesn’t come to people who are blank slates, but presumes that they know a lot of things. It presumes they know that there’s a God, that they’re accountable to Him, that He demands particular things, and that they’ve violated these demands and thus stand guilty before Him. In other words, the gospel presupposes knowledge of the law. The law has a certain priority to the gospel. A person can know the law without knowing the gospel, but no one can understand the gospel without understanding the law first.

Yet the gospel depends on the natural law and not just on the law revealed in Scripture, for the church proclaims the gospel as good news to all people, and not simply to Jews trained under Moses. It’s useful to return to Romans at this point. The basic movement of the first half of Romans is not difficult to see, despite the occasional objection. After a greeting and introduction, Paul levels an indictment against the entire human race (1:18-3:20) and then explains the good news of salvation in Christ (3:21-8:39). In Reformation terms, the first focuses on the law and the second on the gospel. In the indictment, natural law plays a crucial role. As considered above, Paul appeals to the natural revelation of God and His will to establish Gentile humanity’s knowledge of sin and God’s justice in the coming judgment. Of course, Paul also ascribes a similar task to the Mosaic law with respect to Jews. But it’s important to recognize that if only the Mosaic law provides knowledge of God and sin, the gospel would make sense only to Jews. Because Paul was the apostle to the Gentiles (Rom 1:1; 15:16), he makes clear that the gospel is for everyone. For those without training in the Old Testament law, the natural law provides the knowledge of sin and judgment that makes the gospel coherent.

The natural law itself doesn’t reveal the good news of salvation. There’s a natural law, but there’s no natural gospel. A conception of natural law does, however, provide theological explanation for why the Son of God became incarnate, died, and rose again. The church doesn’t preach the gospel into a vacuum, but to real people whom God created for good purposes and who failed to attain those purposes. It preaches to people who are hurt and needy—hurt and needy not because they’re lost in a sea of chaos, but because they’re out of alignment with the moral order by which God governs this world. Natural law explains the biblical teaching that, deep down, all people know that there’s a God, a moral order of the world, and a final judgment. Thanks to the natural law, every person is ready, at some level, to hear and to understand the gospel, even before any Christian explains it to him. If Protestants eliminate natural law from their theology, they deprive the gospel of the scaffold on which it takes shape.

Conclusion

Readers who are orthodox Protestant Christians—heirs of the Reformation—probably already believe that there’s a natural law, whether they realize it or not. That’s because such readers believe that the world God created has objective meaning and purpose, that God will judge the whole world justly on the last day, and that the gospel of Jesus Christ ought to be proclaimed to all people, who are ready to hear it because they know they are sinners alienated from God. To affirm these things is to affirm, at least implicitly, that God reveals His universal moral law in the natural order, as this article has argued. But if that’s the case, then recognizing and acknowledging the reality of natural law explicitly should help Protestants make more sense of the Christian faith and of the world in which they live. The renaissance of interest in natural law in many Protestant circles in recent years is thus encouraging, even if much work remains to be done.

David VanDrunen (JD, Northwestern University School of Law; PhD, Loyola University Chicago) is a minister in the Orthodox Presbyterian Church. He is the Robert B. Strimple Professor of Systematic Theology and Christian Ethics at Westminster Seminary California and was a Hentry Luce III Fellow in Theology in 2016-17. He is the author or editor of eleven books, including Divine Covenants and Moral Order: A Biblical Theology of Natural Law (Eerdmans, 2014).


[1] This essay is based on a lecture at the Davenant Institute’s Denver Regional Convivium Irenicum at Colorado Christian University, in March 2018. I presented a similar lecture at Grove City College in November 2016. For a more detailed and scholarly discussion of the same issues, see my “Natural Law for Reformed Theology: A Proposal for Contemporary Reappropriation,” Journal of Reformed Theology 9 (2015): 117-30.

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