"Go, therefore, and make disciples of all nations, baptizing them in the name of the Father, and of the Son, and of the Holy Spirit, teaching them to observe all that I have commanded you." (Mt 28:19-20)
Thus, the teaching mission of the Church comes from Christ himself. The responsibility for fulfilling that mandate passes on unchanged to the bishops and to all Catholics.
Catechesis is the act of handing on the Word of God intended to inform the faith community and candidates for initiation into the Church about the teachings of Christ transmitted by the Apostles. It also involves the lifelong effort of forming people into witnesses to Christ and opening their hearts to the spiritual transformation given by the Holy Spirit. " USCCB