Because of fleshly lusts, God's regenerate children need the daily instruction and admonition, of the Law in this life. But they also need frequent punishments. So they will follow God's Spirit, as it is written: It is good for me that I was afflicted, that I might learn Your statutes. (Psalm 119:71)
I discipline my body and keep it under control, lest after preaching to others I myself should be disqualified. (1 Corinthians 9:27)
If you are left without discipline, in which all have participated, then you are illegitimate children and not sons. (Hebrews 12:8)
Dr. Luther explained this in the Epistle [Ephesians 4:22-28].
We must explain what the Gospel does and Law's office in this matter, regarding believers' good works.
The Law says it is God's will that we should walk in a new life. But it does not give the power to do it. The Holy Spirit renews the heart. He is given and received, not through the Law, but through the preaching of the Gospel. Thereafter, the Holy Spirit uses the Law in order to teach the regenerate from it and to point out and show them in the Ten Commandments what is the "will of God, what is acceptable and perfect" in what "good works, which God prepared beforehand, that we should walk". (paragraphs 9-12)
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.