The Sacrament of Holy Orders
When Jesus had called the Twelve together, he gave them power and authority to drive out all demons and to cure diseases, and he sent them out to preach the kingdom of God and to heal the sick. He told them: “Take nothing for the journey—no staff, no bag, no bread, no money, no extra tunic. Whatever house you enter, stay there until you leave that town. If people do not welcome you, shake the dust off your feet when you leave their town, as a testimony against them.” So they set out and went from village to village, preaching the gospel and healing people everywhere.
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
Source – Catechism of the Catholic Church
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