Natural law theory refers to the idea that there is an external moral order that God has brought into existence. That moral order is an extension of God’s reason and God’s will, which he has knit into the fabric of the universe because of his eternal law. But it also refers to the fact that human beings, in principle, even in a state of sin with the Noahic effects of the fall, can have access to some principles of the moral law, even in spite of our sin.
It means that as Christians—as Protestant Christians—we recognize that sin has impacted the will. It has impacted reason. But even non-Christians have some access to the moral law. This is a principle we see from Romans 1. Paul talks about how the problem in society that he’s indicting in Romans 1 is not that the audience he’s condemning is not aware of the natural law. They are aware of the natural law. What they’re doing, Paul says, is that they’re suppressing the truth in unrighteousness. They’re holding what they know to be true and suppressing it. They’re holding it down, which means, from my vantage point, that the biggest issue with the natural law today is not really our knowledge of it; it’s the will’s lack of desire to follow it.
Obviously, reason and will have both been corrupted by sin, but the natural law tradition holds that sin has not extinguished knowledge, at least some minimal knowledge of the moral law. The reason that we have to champion and prioritize the natural law is because we have to figure out how to have common life together with individuals in our society who aren’t Christians.
Now, please hear me. This doesn’t mean that when we utilize the natural law that we don’t talk about Jesus. If the natural law is ever used to the exclusion of mentioning the name of Jesus or not mentioning Scripture or Scripture’s authority, that’s an improper use of the natural law. Rather, what the natural law allows us to do is to look at our neighbor and the problems confronting our neighbors in society and say, Okay, something is going awry right here. Why is that? Is that simply because we’ve just randomly decided to live this way and not that way? Or is it the fact that we have as a society deviated from certain normative scripts that we are supposed to identify and live within because that’s where our flourishing is to be found?
It’s important for Christians to care about the natural law because it gives us that moral language to relate to those in our society who may not be Christians, but still have some awareness of a moral law and the existence of a moral grain to the universe.
Right now in contemporary Western America, we’re going through this really tragic controversy around the transgender issue. What’s really fascinating is we’re seeing a lot of non-Christians beginning to raise objections to the transgender movement because they’re recognizing that it seems impossible for us to live against our embodiment as male and female without certain problems arising.
So in a society that champions femininity, how do you champion femininity and authentic femininity when you have men who want to identify as women as well? And that’s a principle of the natural law. Because the natural law is speaking to the existence of that created moral order, we might use the language of creation order that God has knit a moral order. He’s embedded it within creation, which means that every single human being—because they are members of creation—can have at least some access to their knowledge of the natural law, which then gives us an ability to communicate with them.