You might remember that the Lutheran Reformation was largely built on a renewed emphasis on the grace of God, which brings salvation. Salvation is by grace through faith, not based on works of the law (Ephesians 2:8-9). This leads some to suggest that Lutherans should be called "antinomians" - literally, those who are opposed to God's law. And, at times, there have been groups of Lutherans who were willing to go along with this, even suggesting that doing good works in accord with God's law could endanger our salvation.
The problem with an emphasis like this is clear and simple. The Bible consistently presents statements we would describe as "law" from God, as good things, and in contexts that are essential to living in an ordered society.
Before we get too far ahead of ourselves, though, let's get two quick definitions. They're simple, but precise. Speaking biblically "law" is what we are told we need to do. "Gospel," on the other hand, is what God has done for us. I make those definitions because Lutherans have a particular understanding of matters of law and gospel, which other church bodies don't approach very well. For instance, it's normal to hear a Baptist or a Presbyterian speak of "gospel imperatives." A Lutheran will reject that out of hand. There's no command involved in what God has done for us. A "gospel imperative" is an oxymoron. The confusion of law and gospel is at the root of all sorts of troubles involving our understanding of the nature of salvation, the preservation of Christians, the role of the Church in society, and the way a Christian needs to live life. This distinction of law and gospel is one of the true developments of the Lutheran Reformation. It sets Lutherans apart.
God's law is good. In essence, it does three things. These three uses of the law have been identified in other Christian traditions, though they are sometimes listed in a different order. God's law acts as a restraint for society. It does things like prohibit murder, protect private property, tell people they need to treat others ethically, etc. Sometimes this is called a "curb." It prevents you from entering into sin as easily as you might.
A second use of the law is to show us our failure. For instance, God's law tells husbands and wives to be faithful to each other. We can recognize that as soon as we are tempted toward unfaithfulness, even if nobody else sees it, the all-knowing God does see it. We are made aware of it. This isn't entirely bad news, though. As we see our sin, looking into the mirror of God's law, we are moved to sorrow that we are sinful, to ask God for forgiveness, and to receive his restorative love. We all sin daily in many ways. God's law is there, defining sin in a concrete way, and moving us to look for our hope in the gospel, what God has done for us to bring us forgiveness, life, and salvation.
A third use of the law is to show us what is pleasing to God. It gives us ideas of how we can live our lives in a way that accords with God's mercy and grace. This one is a little harder to unpack. As an example, though, God's law tells us we are to love and serve our neighbors. That's a rather vague standard, though. It's not immediately clear what that entails. Once we start thinking about what our neighbors need, as well as what is pleasing to God, we may begin to perceive specific things that we can do for others that agree with God's law. Maybe that takes the form of supporting local charities. Maybe it involves scooping snow off the elderly neighbor's sidewalk. Maybe it means giving the neighbor kid a high five on report card day, or going to the band concert or school play because we know someone who needs encouragement. When we act in our society in ways that are pleasing to God, we serve as God's hand extended to our community. This is a very good thing.
God's law is good. We have to remember that above all. Though in light of God's law we see our sin and failure, it's still good. It shows us what we need to do, and we do it because God has given us a standard. He tells us what good and evil are. And he, being the good God, wants to use his law in us and in everyone around us to bring blessing to our neighbors. We are not ashamed of God's law. We give thanks that God cares enough for us and our neighbors to give us such a gift.