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 which give praise to His name. The entire body of the faithful, anointed as 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.
It is not only through the sacraments and the ministries of the Church that the Holy Spirit sanctifies and leads the people of God and enriches it with virtues, but, "allotting his gifts to everyone according as He wills, He distributes special graces among the faithful of every rank. By these gifts He makes them fit and ready to undertake the various tasks and offices which contribute toward the renewal and building up of the Church, according to the words of the Apostle: "The manifestation of the Spirit is given to everyone for profit". These charisms, whether they be the more outstanding or the more simple and widely diffused, are to be received with thanksgiving and consolation for they are perfectly suited to and useful for the needs of the Church. Extraordinary gifts are not to be sought after, nor are the fruits of apostolic labor to be presumptuously expected from their use; but judgment as to their genuinity and proper use belongs to those who are appointed leaders in the Church, to whose special competence it belongs, not indeed to extinguish the Spirit, but to test all things and hold fast to that which is good.
Source: Dogmatic Constitution on the Church, 'Lumen Gentium', n° 12.