From the Catechism:
77 "In order that the full and living Gospel might always be preserved in the Church the apostles left bishops as their successors. They gave them their own position of teaching authority." Indeed, "the apostolic preaching, which is expressed in a special way in the inspired books, was to be preserved in a continuous line of succession until the end of time."
79 The Father's self-communication made through his Word in the Holy Spirit, remains present and active in the Church: "God, who spoke in the past, continues to converse with the Spouse of his beloved Son. And the Holy Spirit, through whom the living voice of the Gospel rings out in the Church - and through her in the world - leads believers to the full truth, and makes the Word of Christ dwell in them in all its richness."
85 "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.
86 "Yet this Magisterium is not superior to the Word of God, but is its servant. It teaches only what has been handed on to it. At the divine command and with the help of the Holy Spirit, it listens to this devotedly, guards it with dedication and expounds it faithfully. All that it proposes for belief as being divinely revealed is drawn from this single deposit of faith."
87 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.
88 The Church's Magisterium exercises the authority it holds from Christ to the fullest extent when it defines dogmas, that is, when it proposes truths contained in divine Revelation or also when it proposes in a definitive way truths having a necessary connection with them.
91 All the faithful share in understanding and handing on revealed truth. They have received the anointing of the Holy Spirit, who instructs them and guides them into all truth.
92 "The whole body of the faithful. . . cannot err in matters of belief. This characteristic is shown in the supernatural appreciation of faith (sensus fidei) on the part of the whole people, when, from the bishops to the last of the faithful, they manifest a universal consent in matters of faith and morals."
94 Thanks to the assistance of the Holy Spirit, the understanding of both the realities and the words of the heritage of faith is able to grow in the life of the Church:
- "through the contemplation and study of believers who ponder these things in their hearts"; it is in particular "theological research [which] deepens knowledge of revealed truth".
- "from the intimate sense of spiritual realities which [believers] experience," the sacred Scriptures "grow with the one who reads them."
- "from the preaching of those who have received, along with their right of succession in the episcopate, the sure charism of truth".
95 "It is clear therefore that, in the supremely wise arrangement of God, sacred Tradition, Sacred Scripture and the Magisterium of the Church are so connected and associated that one of them cannot stand without the others. Working together, each in its own way, under the action of the one Holy Spirit, they all contribute effectively to the salvation of souls."