“Religious instruction preparatory to admission to church membership is as old as Christianity itself, but it assumed very different shapes in different ages and countries. In the first three or four centuries (as also now on missionary ground) it always preceded baptism, and was mainly addressed to adult Jews and Gentiles. It length and method it freely adapted itself to various conditions and degrees of culture. The three thousand Jewish converts on the day of Pentecost, having already a knowledge of the Old Testament, were baptized simply on their profession of faith in Christ, after hearing the sermon of St. Peter. Men like Cornelius, the Eunuch, Apollos, Justin Martyr, Tertullian, Cyprian, Jerome, Ambrose, Augustine, needed but little theoretical preparation, and Cyprian and Ambrose were elected bishops even while yet catechumens. At Alexandria and elsewhere there were special catechetical schools of candidates for baptism. The basis of instruction was the traditional rule of faith or Apostles’ Creed, but there were no catechisms in our sense of the term; and even the creed which the converts professed at baptism was not committed to writing, but orally communicated as a holy secret. Public worship was accordingly divided into a missa catechumenorum for half-Christians in process of preparation for baptism, and a missa fidelium for baptized communicants or the Church proper.
“With the union of Church and State since Constantine, and the general introduction of infant baptism, catechetical instruction began to be imparted to baptized Christians, and served as a preparation for confirmation or the first communion. It consisted chiefly of the committal and explanation, (1) of the Ten Commandments, (2) of the Creed (the Apostles’ Creed in the Latin, the Nicene Creed in the Greek Church), sometimes also of the Athanasian Creed and the Te Deum; (3) of the Lord’s Prayer (Paternoster). To these were added sometimes special chapters on various sins and crimes, on the Sacraments, and prayers. Councils and faithful bishops enjoined upon parents, sponsors, and priests the duty of giving religious instruction, and catechetical manuals were prepared as early as the eighth and ninth centuries, by Kero, monk of St. Gall (about 720); Notker, of St. Gall (d. 912); Otfried, monk of Weissenbourg (d. after 870), and others. But upon the whole this duty was sadly neglected in the Middle Ages, and the people were allowed to grow up in ingnorance and superstition. The anti-papal sects, as the Albingenses, Waldenses, and the Bohemian Brethren, paid special attention to catechetical instruction.
“The Reformers soon felt the necessity of substituting evangelical Catechisms for the traditional Catholic Catechisms, that the rising generation might grow up in the knowledge of the Scriptures and the true faith. Of all the Protestant Catechisms, those of Luther follow most closely the traditional method, but they are baptized with a new spirit” (Schaff, Creeds of Christendom, Vol. I: The History of Creeds, pp. 245-246).