Moses experienced the glory of God when he received the Law from God. Moses put a veil over his face because his appearance frightened the people. The Law of God is frightening to people who do not know the mercy of God. When Paul saw the glory of Christ and was born again he no longer feared the Law, for Christ has satisfied the demands of the Law. Paul now saw the Law as desirable because it shows those who are born again how we can walk with the Lord.
God's Law is useful (1) because external discipline and decency are maintained by it against wild, disobedient people; (2) likewise, through the Law people are brought to a knowledge of their sins; and also, (3) when people have been born anew by God's Spirit, converted to the Lord, and Moses's veil has been lifted from them [2 Corinthians 3:13-16], they walk in the Law [Psalm 119:1]. A disagreement has arisen between a few theologians about this third use of the Law. One side taught and maintained that the regenerate do not learn the new obedience from the Law. They argued that this teaching about good works is not to be encouraged from the Law. They say the regenerate have been made free by God's Son, have become the temples of His Spirit, and therefore do freely of themselves what God requires of them. They act by the prompting of the Holy Spirit, just as the sun by itself completes its ordinary course in the sky. The other side taught the following: The truly believing are certainly moved by God's Spirit. According to the inner man, they do God's will from a free spirit. Yet the Holy Spirit uses the written Law to instruct them. The believing learn to serve God, not according to their own thoughts, but according to His written Law and Word. This is a sure standard of a godly life. The Law shows how to order a life in accordance with God's eternal will. (paragraphs 1-3)
Condensed from CONCORDIA: THE LUTHERAN CONFESSIONS, copyright 2005,2006 by Concordia Publishing House. Used by permission. All rights reserved. To purchase a copy of CONCORDIA, call 800-325-3040.