Bishop Ricken being ordained by Saint John Paul II
Holy Orders is the sacrament through which the mission entrusted by Christ to the 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 (bishop), presbyterate (priest), and diaconate (deacon). (CC 1526)
The whole Church is a priestly people. Through Baptism all the faithful share in the priesthood of Christ. This participation is called the "common priesthood of the faithful." Based on this common priesthood and ordered to service, there exists another participation in the mission of Christ: the ministry conferred by the sacrament of Holy Orders, where the task is to serve in the name and in the person of Christ the Head in the midst of the community. (CC 1591)
The ministerial priesthood differs in essence from the common priesthood of the faithful because it confers a sacred power for the service of the faithful. The ordained ministers exercise their service for the People of God by teaching (munus docendi), divine worship (munus liturgicum) and pastoral goverance (munus regendi).