Protestantism has always had a somewhat ambiguous relationship with the Law – understood both as the natural and revealed moral law. With its emphasis on justification by grace through faith alone, Protestantism has frequently been accused by critics of lapsing into antinomianism. That is, if we are saved by grace, independently of whether we keep the law, what motive do we have to be good people?
The Reformers were aware of this charge, of course (just as Paul was, cf. Romans 6), and early on they developed an approach to the Law that we may with some fairness call the “classical Protestant” position. For both Luther and Calvin, the Law has multiple uses:
The Political Use: The Law serves as a check on human sin, protecting the vulnerable and preserving society. Since we can’t assume that people will spontaneously, e.g. respect the lives and property of others, the political authorities are charged with enforcing external adherence to the law.
The Spiritual Use: This is arguably the most important use of the Law for the Reformers. When we see how far short we fall of meeting our moral obligations, we become receptive to the message of grace. The Law “convicts” us by showing us where we have failed. We then realize that we can’t save ourselves by seeking to meet the requirements of the Law. The teachings of Jesus only intensify this dilemma by turning our attention to our inner states and motivations (“lusting in the heart,” “hating one’s brother,” etc.). The Law reveals our sin and we are forced to rely on Christ alone for our salvation.
The Pedagogical Use: The so-called third use of the Law has been the most controversial, and there is debate about whether Luther ever endorsed it. But it’s clear that Calvin thought it was important, and it has been an important part of much Protestant thought ever since. In this capacity, the Law provides guidance for the Christian life. Though we are saved by Christ alone, the Law shows us the proper shape the Christian life should take as a response to God’s grace. According to Calvin, the Law helps Christians “to learn more thoroughly each day the nature of the Lord’s will to which they aspire, and to confirm them in the understanding of it.”
Many Protestants (especially Lutherans) object to the “third use” of the Law, because they think it threatens to become a backdoor to legalism and works-righteousness. And that it risks making us content with a moral minimalism rather than spurring us on to daring acts of love. Calvinists respond that the Law (understood broadly to include the Decalogue and the precepts and example of Christ) provides a needed concreteness to the Christian life. If we rely on vague norms like “love,” “justice” or “peace” without giving them a definite shape, they can become justifications for pretty much any position, and the Christian life becomes hostage to our pet political nostrums (That this has in fact happened in many a Protestant church, liberal and conservative, scarcely needs pointing out!).
Put another way, Lutherans and Calvinists agree that grace provides the motive for doing good works. As Luther said, good works are the “fruit” of faith. But they appear to disagree on how we determine the content of what count as good actions. To those who emphasize the third use of the Law, there will be norms for Christian living that are always binding. Those who say we should rely on creative responses to new situations informed by the Spirit will tend to be more consequentialist in their moral reasoning.
While I agree that there is a genuine problem of “legalism” when we emphasize the Law as a guide to Christian living, I think the greater danger lies in thinking that we can do without it. The result seems to me to be a loss of a distinctively Christian pattern of life. As theologian Reinhard Hütter says, “God’s commandment is nothing else than the concrete guidance, the concrete social practice that allows us to embody our communion with God in concrete creaturely ways.” Living in communion with God has a definite shape, one taught to us by the Law, by the example of Jesus (who came to fulfill rather than abolish the Law), and by the Apostles and Saints of the church catholic throughout the ages. It is precisely this concrete practice, as embodied in the church’s life, which shows us what life in community with God is supposed to look like. The point is not that the Law saves us, but that God saves us for a particular kind of life, and we see that life reflected in the Law.