God desires all men to be saved and to come to the knowledge of the truth: that is, of Christ Jesus. Christ must be proclaimed to all nations and individuals, so that this revelation may reach to the ends of the earth: “God graciously arranged that the things he had once revealed for the salvation of all peoples should remain in their entirety, throughout the ages, and be transmitted to all generations.” 2 Cor 1:20; 3:16-4:6.
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. Mt 28:19-20; Mk 16:15.
The task of giving an authentic interpretation of the Word of God, whether in its written form or in the form of Tradition, has been entrusted to the living teaching office of the Church alone. Its authority in this matter is exercised in the name of Jesus Christ. This means that the task of interpretation has been entrusted to the bishops in communion with the successor of Peter, the Bishop of Rome.
Mindful of Christ's words to his apostles: "He who hears you, hears me," the faithful receive with docility the teachings and directives that their pastors give them in different forms.