…The Ten Commandments bind us still as they were then given to a people that were at that time under the covenant of grace made with Abraham, to show them what duties are holy, just and good, well-pleasing to God, and to be a rule for their conversation. The result of all is that we must still practice moral duties as commanded by Moses, but we must not seek to be justified by our practice. If we use them as a rule of life, not as conditions of justification, they can be no ministration of death, or killing letter to us.
-Walter Marshall, The Gospel Mystery of Sanctification, Chapter 6, Kindle Loc. 1235-39 (Get a free copy for Kindle HERE).
The traditional Reformed understanding of God’s Law is that it has three continuing uses:
1. It is to restrain evil (Civil Use)
2. It is to reveal sin and lead us to the Savior (Pedagogical Use)
3. It is to direct the living of the Christian life (Moral or Normative Use)
Marshall nails the third use here: having been accepted by God the Father solely on the basis of the finished work of Christ, we are now to strive, by the power of the Spirit at work within us, for new obedience. The problem emerges when we slip into the idea that our obedience now somehow contributes to God’s acceptance of us. At that point the third use of the Law is wholly perverted and becomes an agent of death rather than life, disobedience rather than obedience.