CCC 875No one can give himself the mandate and the mission to proclaim the Gospel. The one sent by the Lord does not speak and act on his own authority, but by virtue of Christ's authority; not as a member of the community, but speaking to it in the name of Christ. No one can bestow grace on himself; it must be given and offered.
This fact presupposes ministers of grace, authorized and empowered by Christ. From him, bishops and priests receive the mission and faculty ("the sacred power") to act in persona Christi Capitis.
The ministry in which Christ's emissaries do and give by God's grace what they cannot do and give by their own powers, is called a "sacrament" by the Church's tradition.
Ministers are meant to be “slaves of Christ.” (imitate Christ who took the form of a slave)
College of Bishops: Likewise, it belongs to the sacramental nature of ecclesial ministry that it have a collegial character.
Begun when Jesus instituted the twelve as "the seeds of the new Israel and the beginning of the sacred hierarchy", together, they were also sent out together, and their fraternal unity would be at the service of the fraternal communion of all the faithful.
Each bishop exercises his ministry from within the episcopal college, in communion with the bishop of Rome.
Sanctifying Office: Administering the sacraments, especially the Eucharist.
Communicating grace through the authority given by Christ.
Governing Office: Bishops, as emissaries of Christ, govern the particular Church assigned to them. Their authority is exercised in communion with the whole Church under the guidance of the Pope.
Teaching Office (Magisterium): to preach the Gospel to all men, endowed with the authority of Christ. To clarify, defend, explain the faith.
Christ confers on the teaching office the gift of infallibility to preserve the magisterium from errors regarding the truth of salvation (faith and morals).
It is this Magisterium's task to preserve God's people from deviations and defections and to guarantee them the objective possibility of professing the true faith without error → the prophets in the OT foreshadow this.
When the Church through its supreme Magisterium proposes a doctrine "for belief as being divinely revealed," and as the teaching of Christ, the definitions "must be adhered to with the obedience of faith."
CCC 2032 The Church, the "pillar and bulwark of the truth," "has received this solemn command of Christ from the apostles to announce the saving truth." "To the Church belongs the right always and everywhere to announce moral principles, including those pertaining to the social order, and to make judgments on any human affairs to the extent that they are required by the fundamental rights of the human person or the salvation of souls."
CCC 2034 The Roman Pontiff and the bishops are "authentic teachers, that is, teachers endowed with the authority of Christ, who preach the faith to the people entrusted to them, the faith to be believed and put into practice.
CCC 2035 The supreme degree of participation in the authority of Christ is ensured by the charism of infallibility. This infallibility extends as far as does the deposit of divine Revelation; it also extends to all those elements of doctrine, including morals, without which the saving truths of the faith cannot be preserved, explained, or observed.
CCC 2036 The authority of the Magisterium extends also to the specific precepts of the natural law, because their observance, demanded by the Creator, is necessary for salvation. In recalling the prescriptions of the natural law, the Magisterium of the Church exercises an essential part of its prophetic office of proclaiming to men what they truly are and reminding them of what they should be before God.
The natural law is essential to follow for salvation.