Religious instruction and formation in the faith.

The instruction and spiritual formation of the catechumens, neophytes and candidates.

(and Catechism): the procedure of mentoring a novice in order that he/she be accepted into the Christian faith by baptism. The novice was called the catechumen.

Taken in the sense of "the art of teaching" and "the knowledge imparted by teaching", this term is synonymous with CATECHISM.