Until now consciences were plagued with [a false] 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, such as the ungodly and devil have [James 2:19]. Rather, it means a faith that believes, not merely the history, but it believes this article: the forgiveness of sins. We have grace, righteousness, and forgiveness of sins through Christ.
The person who knows that he also has a Father who is gracious to him through Christ truly knows God [John 14:7]. He also knows that God cares for him [1 Peter 5:7], 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 3:11-12] and expect no good from Him. Augustine also warns his readers about the word faith and teaches that the term is used in the Scriptures, not for the knowledge that is in the ungodly, but for the confidence that consoles and encourages the terrified mind. (Augsburg Confession XX 19-26)