Fathers of Christian Doctrine

Confraternity of Christian Doctrine is an association established in Rome in 1562 for the purpose of giving religious education. Its modern usage, often abbreviated CCD or C.C.D., is a religious education program of the Roman Catholic Church, normally designed for children.

In the thirteenth century, the Apostles' Creed and the Lord's Prayer formed the general basis of religious instruction. All the faithful within the Catholic Church had to know them by heart, and parish priests were commanded to explain them on Sundays and festivals. Eventually, the range of instruction was widened to include the Commandments, the sacraments, the virtues and vices.

In 1281 the Synod of Lambeth, England, ordered priests to explain these truths of faith four times a year. The Provincial Council of Lavours, France, in 1368, expanded this and commanded priests to give instruction on all Sundays and feast days. This council also published a catechism to serve as a textbook for the clergy in giving instructions in Christian doctrine, which was followed in all the dioceses of Languedoc and Gascony. Similar manuals were published elsewhere.

Partly in response to the challenge to uniformity posed by the Reformation, the Council of Trent stated that church reform must begin with the religious instruction of the young. The Council issued the "Catechismus ad Parochos", and decreed that throughout the Church instructions in Christian doctrine should be given on Sundays and festivals.

...
Wikipedia