The first manuals of instruction of this kind were prepared for the use of the priests, to guide them in the questioning of penitents, but with the discovery of the art of printing popular hand-books for the use of the laity became more and more common, and with certain of these manuals Luther was familiar.[3] From the beginning of his ministry at Wittenberg, Luther had preached from time to time upon the Ten Commandments and the Lord's Prayer. In 1518 his friend Agricola published a series of sermons on the Lord's Prayer which Luther had preached in Lent, 1517.[4] In the same year Luther published his own _Kurze Auslegung der zehn Gebote, ihrer Erfüllung und Uebertretung_.[5] The year 1519 saw the publication of the _Kurze Form das Paternoster zu verstehen und zu beten_, and the _Kurze und gute Auslegung des Vaterunsers vor sich und hinter sich_.[7] The _Treatise on Good Works_[8], which is essentially an exposition of the decalogue, was written in the early months of 1520. During the same period the mind of Luther was frequently occupied with the abuses of the confessional, as we learn from the _Confitendi Ratio_,[9] and the _Kurze Unterweisung wie man beichten soil_.[10] All the material for the first and third parts of the present work was, therefore, in hand and had appeared in print before 1520. In 1520 the Kurze Form came from the press.[11] It consists of three separately composed expositions of the three chief subjects of catechetical instruction in the Middle Ages. The expositions of the Commandments and the Lord's Prayer are reproductions of the _Kurze Auslegung der zehn Gebote_ and the _Kurze Form das Paternoster zu verstehen und zu beten_. The treatment of the Apostles' Creed is new, as is also the Introduction, in which Luther sets forth the relation of the three parts to one another in the unity of the Christian life. The work is not scientific and theological, but popular and religious. Its purpose is primarily devotional, not pedagogical. The mediæval root out of which it grew is not to be denied. The catalogue of transgressions and fulfilments attached to the explanation of the decalogue shows that it is intended to be a manual for penitents, but the spirit in which the Creed and the Lord's Prayer are explained is not mediæval, and the manner in which the explanations of the decalogue are simplified and rid of the excrescences of the XV Century hand-books shows the new evangelical conception of confession to which Luther had attained. The division of the Creed into three articles instead of the traditional twelve marks an epoch in the development of catechetical instruction. The little book contains passages of rare beauty, clouded at times, we fear, by the new language into which it has here been put, and seldom has the _Wesen des Christentums_ been more simply and tellingly set forth than in the treatment of the Creed.