Believers are not completely renewed in this world. The old Adam clings to them right up to the grave. Therefore, the struggle between the spirit and the flesh remains in them. They delight in God's Law according to the inner man [Romans 7:22], but the law in their members struggles against the law in their mind. Therefore, they are never without the Law. Nevertheless, they are not under [Romans 6:14], but in the Law. They live and walk in the Law of the Lord, and yet do nothing in the Law because of force.
As far as the old Adam is concerned, which still clings to them, he must be driven not only by the Law, but also by punishments. Nevertheless, he does everything against his will and under coercion, no less than the godless are driven and held in obedience by the Law's threats (1 Corinthians 9:27; Romans 7:18-19).
This doctrine of the Law is needed by believers in order that they may not make up a holiness and devotion of their own. Using God's Spirit as an excuse, they must not set up a self-chosen worship, without God's Word and command. For it is written:
"You shall not do according to … whatever is right in [your] own eyes," but "be careful to obey all these words that I command you," "you shall not add to it or take from it." (Deuteronomy 12:8,28,32) (paragraphs 18-20)
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.