The holy people of God shares also in Christ’s prophetic office; it spreads abroad a living witness to him, especially by means of a life of faith and charity and by offering to God a sacrifice of praise, the tribute of lips that gives praise to his name. The entire body of the faithful, anointed a they are by the Holy One, cannot err in matters of belief. They manifest this special property by means of the whole peoples’ supernatural discernment in matters of faith when ‘from the Bishops down to the last of the lay faithful’ they show universal agreement in matters of faith and morals. That discernment in matters of faith is aroused and sustained by the Spirit of truth. It is exercised under the guidance of the sacred teaching authority, in faithful and respectful obedience to which the people of God accepts that which is not just the word of men but truly the word of God. Through it, the people of God adheres unwaveringly to the faith given once and for all to the saints, penetrates it more deeply with right thinking, and applies it more fully in its life.
Lumen gentium, 12