Until now  consciences were plagued with the doctrine of works. They did not hear consolation from the Gospel. Some people were driven by conscience into the desert and into monasteries, hoping to merit grace by a monastic life. Some people came up with other works to merit grace and make satisfaction for sins. That is why the need was so great for teaching and renewing the doctrine of faith in Christ, so that anxious consciences would not be without consolation but would know that grace, forgiveness of sins, and justification are received by faith in Christ.
People are also warned that the term faith does not mean simply a knowledge of a history [of Christ's suffering and his resurrection from the dead], such as the ungodly and devil have [James 2:19]. Rather, it means a faith that believes, not merely the history, but also the effect of the history. In other words, it believes this article: the forgiveness of sins. We have grace, righteousness, and forgiveness of sins through Christ.
The person who knows that he has a Father who is gracious to him through Christ truly knows God [John 14:7], and he calls upon God [Romans 10:13]. In a word, he is not without God, as are the heathen. For devils and the ungodly are not able to believe this article: the forgiveness of sins. Hence they hate God as an enemy [Romans 8:7]. (paragraphs 19-25)
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.