The remembering of God's great acts of mercy is an appropriate act of grateful praise to God and a source of spiritual strength. It is important that those who participate understand the greatness of God's mercy toward us. This is true of the celebration of the incarnation of the Son of God, God's gift of a Savior.
The use of the Sacrament, in which faith enlivens terrified hearts, is a service of the New Testament. That is because the New Testament requires spiritual inclinations, making dead and alive. Christ instituted the Sacrament for this use, since He commanded the disciples to do this in remembrance of Him. Remembering Christ is not the use-less celebration of a show. It is not something set up for the sake of example. Rather, it is remembering Christ's benefits and receiving them through faith, to be enlivened by them. So Psalm 111:4-5 says, "He has caused His wondrous works to be remembered; the Lord is gracious and merciful. He provides food for those who fear Him." The Sacrament illustrates that God's will and mercy should be discerned in the ceremony. Faith that grasps mercy enlivens. This is the chief use of the Sacrament. It is clear who are fit for the Sacrament (terrified consciences) and how they use it.
The sacrifice also is added. For there are several reasons with one purpose. After a conscience encouraged through faith has determined from what terrors it is freed, it fervently gives thanks for Christ's benefit and passion. It also uses the ceremony itself to God's praise, to show its gratitude by this obedience. It declares that it holds God's gifts in high esteem. So the ceremony becomes a sacrifice of praise. (paragraphs 71-74)
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.