This book contains Luther’s small and large catechisms, which grew out of practical religious needs, and ultimately out of the institution of the confessional. He was grieved by what he considered the spiritual wretchedness of Christians, and he saw it as his duty to teach them the doctrine of eternal salvation. These catechisms were meant both for schoolchildren and for adults, and Luther believed that they contained all the doctrinal information necessary for salvation. The three principal parts of the catechism—the Ten Commandments, the Creed, and the Lord’s Prayer—was the basis of popular education in the church. Luther valued them highly, declaring that they contained the substance of the Scriptures, all essential homiletic material, and the essentials of Christian knowledge.