Christians are not under the Law but under grace. For by faith in Christ the persons are freed from the Law's curse and condemnation. Their good works, although they are still imperfect and impure, are acceptable to God through Christ. Because, in so far as they have been born anew according to the inner man, they do what is pleasing to God. They act not by coercion of the Law, but by the renewing of the Holy Spirit, voluntarily and spontaneously from their hearts. However, they still have a constant struggle against the old Adam.
The old Adam, like an unruly, stubborn ass, is still a part of them. It must be forced to obey Christ. It not only requires the teaching, admonition, force, and threatening of the Law, but it also often needs the club of punishments and troubles. This goes on until the body of sin is entirely put off and a person is perfectly renewed in the resurrection. Then he will need neither the preaching of the Law nor its threats and punishments, just as he will no longer need the Gospel. These belong to this imperfect life. Just as people will see God face-to-face, so they will—through the power of God's indwelling Spirit—do the will of God with unmingled joy, voluntarily, unconstrained, without any hindrance, and with entire purity and perfection. They will rejoice in it eternally. (paragraphs 23-25)
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.