The Catechism in Questions & Answers

698. What is the function of Religious Instruction in church?

In Religious Instruction the children learn from the accounts of human experiences with God: the history of salvation is discussed in reference to the faith life of the children. Contents of faith are deepened, knowledge is promoted, and the interconnections within God’s plan of salvation are explained. In this manner, enduring values are imparted to the children.
Moreover, Religious Instruction should enable students to freely profess their faith.

Plan of salvation, salvation history: see Questions 243. et seq.