ORAL APOSTOLIC TRADITION
The Apostolic Tradition
“Christ the Lord, in whom the entire Revelation of the most high God is summed up, commanded the apostles to preach the Gospel, which had been promised beforehand by the prophets, and which he fulfilled in his own person and promulgated with his own lips. In preaching the Gospel, they were to communicate the gifts of God to all men. This Gospel was to be the source of all saving truth and moral discipline.”
The Catechism of the Catholic Church
. . . continued in apostolic succession**
This living transmission, accomplished in the Holy Spirit, is called Tradition, since it is distinct from Sacred Scripture, though closely connected to it. Through Tradition, "the Church, in her doctrine, life, and worship perpetuates and transmits to every generation all that she herself is, all that she believes."37 "The sayings of the holy Fathers are a witness to the life-giving presence of this Tradition, showing how its riches are poured out in the practice and life of the Church, in her belief and her prayer."38
The apostles entrusted the “Sacred deposit” of the faith (the depositum fidei),45 contained in Sacred Scripture and Tradition, to the whole of the Church. "By adhering to [this heritage] the entire holy people, united to its pastors, remains always faithful to the teaching of the apostles, to the brotherhood, to the breaking of bread and the prayers. So, in maintaining, practicing, and professing the faith that has been handed on, there should be a remarkable harmony between the bishops and the faithful."46
II. The Language of Faith
The Church, “the pillar and bulwark of the truth,” faithfully guards “the faith which was once for all delivered to the saints.” She guards the memory of Christ’s words; it is she who from generation to generation hands on the apostles’ confession of faith.57 As a mother who teaches her children to speak and so to understand and communicate, the Church our Mother teaches us the LANGUAGE of faith in order to introduce us to the understanding and the life of faith.
15And He said to them, "Go into all the world and preach the gospel to all creation.
Hope this helps;)