But by divine institution it is the exclusive task of these pastors alone, the successors of Peter and the other Apostles, to teach the faithful authentically, that is with the authority of Christ shared in different ways; so that the faithful, who may not simply listen to them as experts in Catholic doctrine, must accept their teaching given in Christ’s name, with an assent that is proportionate to the authority that they possess and that they mean to exercise.(20) For this reason the Second Vatican Council, in harmony with the first Vatican Council, teaches that Christ made Peter “a perpetual and visible principle and foundation of the unity of the faith and of communion”(21); and the Supreme Pontiff Paul VI has declared: “The teaching office of the bishops is for the believer the sign and channel which enable him to receive and recognize the Word of God.”(22) Thus, however much the Sacred Magisterium avails itself of the contemplation, life and study of the faithful, its office is not reduced merely to ratifying the assent already expressed by the latter; indeed, in the interpretation and explanation of the written or transmitted Word of God, the Magisterium can anticipate or demand their assent.(23) The People of God has particular need of the intervention and assistance of the Magisterium when internal disagreements arise and spread concerning a doctrine that must be believed or held, lest it lose the communion of the one faith in the one Body of the Lord (cf. Eph 4:4, 5).