Some criteria for assessing Lutheran discussions of law:
1. Can a particular understanding of law make sense of Luther’s criticism of such things as pilgrimages? Luther argued that such actions are not commanded by God and thus we cannot know that they are God-pleasing. Such actions as honoring our parents, however, are commanded by God and so we know we are doing what God wishes when we honor our parents. It seems to me that some recent Lutheran presentations on law cannot make sense of this argument by Luther.
2. Can a particular understanding of law make sense of the sections on the Ten Commandments in Luther’s Large and Small Catechisms? Luther here clearly presents the law as instruction on what persons (Christians included) ought to do. There may be some understandings of a ‘third use of the law’ that are objectionable (e.g., directly deriving legal or political structures from Old Testament models), but that there is a kind of third use, a pedagogical use, in the Catechisms’ discussion of the Commandments seems obvious.
3. Can a particular understanding of law make sense of Ps. 119? We may want to make distinctions between what ‘law’ means in this psalm and what it means when law is contrasted with gospel, but the two uses overlap significantly. In both cases, they involve moral instruction. And the psalmist gives thanks for the law as a blessing: “Oh, how I love thy law! It is my meditation all the day” (v. 97). This psalm is not an obscure passage to be passed over; it has been an important part of Christian prayer
The law always accuses, but it does not only accuse, nor does it only accuse and restrain. It instructs. If that is not Lutheran, then Lutheranism is not biblical.