I. Jesus Himself is the leader of the Church, but He also wanted there to be a visible ministry to continue guiding His Church, able to assure people of what is the true Church, what is the true faith, and what are the true sacraments.

II. "Holy Orders is the sacrament through which the mission entrusted by Christ to His apostles continues to be exercised in the Church until the end of time: thus it is the sacrament of apostolic ministry. It includes three degrees: episcopate, presbyterate, and diaconate." Catechism of the Catholic Church 1536.

III. "This sacrament configures the recipient to Christ by a special grace of the Holy Spirit, so that he may serve as Christ's instrument for His Church. By ordination one is enabled to act as a representative of Christ, Head of the Church, in His triple office of priest, prophet, and king." Catechism of the Catholic Church 1581. Because the recipients of Holy Orders are acting in the person of Christ, they must be men and are preferably celibate. The former requirement is absolute from the sacrament itself. The latter quality has always been preferred and has been universally required in the West for bishops and priests for 900 years.

IV Other walks of life, although not instituted with a sacrament, constitute consecrations to God for His glory and the salvation of humanity.