Catholic Authority

AUTHORITY IN ROMAN CATHOLICISM
In contrast to the Protestant position of sola scriptura, Roman Catholicism finds its source of authority in three areas: the Bible, Tradition, and the teaching authority of the Church, or the Magisterium. Roman Catholic documents state:

Sacred Tradition and sacred Scripture, then, are bound closely together, and communicate one with the other. For both of them, flowing out of the same divine well-spring, come together in some fashion to form one thing, and move toward the same goal. Sacred Scripture is the speech of God as it is put down in writing under the breath of the Holy Spirit. And Tradition transmits in its entirety the Word of God which has been entrusted to the apostles by Christ the Lord and by the Holy Spirit. It transmits it to the successors of the apostles so that, enlightened by the Spirit of truth, they may faithfully preserve, expound and spread it abroad by their preaching. Thus it comes about that the Church does not draw her certainty about all revealed truths from the holy Scriptures alone. Hence, both Scripture and Tradition must be accepted and honored with equal feelings of devotion and reverence.

Sacred Tradition and sacred Scripture make up a single sacred deposit of the Word of God, which is entrusted to the Church. By adhering to it 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 (cf. Acts 2:42 Greek). 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.

But 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.

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.3

Roman authority resides, then, in the “Word of God” as the source and the teaching office of the Church as interpreter.(https://bible.org/seriespage/catholic-theology)