The Sacrament of Holy Orders is the continuation of Christ's priesthood, which He bestowed upon His Apostles; and so, the Catechism of the Catholic Church refers to the Sacrament of Holy Orders as "The Sacrament of Apostolic Ministry." "Ordination" comes from the Latin word ordinatio, which means to incorporate someone into an order. In the Sacrament of Holy Orders, a man is incorporated into the priesthood of Christ, at one of three levels: the episcopate, the priesthood, or the diaconate.

The priesthood was established by God among the Israelites during their exodus from Egypt. God chose the tribe of Levi as priests for the nation. Their primary duties were the offering of sacrifice and prayer for the people. Christ, in offering Himself up for the sins of all humanity, fulfilled the duties of the Old Testament priesthood once and for all. But just as the Eucharist makes that sacrifice present to us today, so the New Testament priesthood is a sharing in the eternal priesthood of Christ. While all believers are, in some sense, priests, some are set aside to serve the Church as Christ Himself did.

There is only one Sacrament of Holy Orders, but there are three levels. The first is that which Christ Himself bestowed upon His Apostles: the episcopate. A bishop is a man who is ordained to the episcopate by another bishop (in practice, by several bishops). He stands in a direct, unbroken line from the Apostles, a condition known as "apostolic succession." Ordination as a bishop confers the grace to sanctify others, as well as the authority to teach the faithful and to bind their consciences. Because of the grave nature of this responsibility, all episcopal ordinations must be approved by the Pope.

The second level of the Sacrament of Holy Orders is the priesthood. No bishop can minister to all of the faithful in his diocese, so priests act, in the words of the Catechism of the Catholic Church, as "co-workers of the bishops." They exercise their powers lawfully only in communion with their bishop, and so they promise obedience to their bishop at the time of their ordination. The chief duties of the priesthood are the preaching of the Gospel, the offering of the Eucharist and the pastoral and spiritual care of those who have been entrusted to him. Catholic priests are normally unmarried and called to be celibate, although some former Anglican married clergy have been granted a special dispensation by the Pope to remain married and be ordained Catholic priests.

The third level of the Sacrament of Holy Orders is the diaconate. Deacons assist priests and bishops, but beyond the reading of the Gospel and distribution of the chalice at Mass, they are granted no special charism or spiritual gift. Married men are allowed to become permanent deacons.

The Sacrament of Holy Orders can be validly conferred only on baptized men, following the example set by Christ and His Apostles, who chose only men as their successors and collaborators. No one can demand ordination; the Church has the authority to determine eligibility for the sacrament. While the episcopate is reserved to unmarried men, the discipline regarding the priesthood varies in East and West. The Eastern Churches allow married men to be ordained priests, while the Western Church insists on celibacy. Once a man has received the Sacrament of Holy Orders, however, he cannot marry.

As the Catechism of the Catholic Church notes: The essential rite of the sacrament of Holy Orders for all three degrees consists in the bishop's imposition of hands on the head of the ordinand and in the bishop's specific consecratory prayer asking God for the outpouring of the Holy Spirit and his gifts proper to the ministry to which the candidate is being ordained. Because of his role as a successor to the Apostles, who were themselves successors to Christ, the bishop is the proper minister of the Sacrament. The grace of sanctifying others that he receives at his own ordination allows him to ordain others.

The Sacrament of Holy Orders, like the Sacrament of Baptism and the Sacrament of Confirmation, can only be received once for each level of ordination. Once a man has been ordained, he is spiritually changed, which is the origin of the saying, "Once a priest, always a priest." He can be dispensed of his obligations as a priest (or even forbidden to act as a priest); but he remains a priest forever.

If you feel called to the priesthood or diaconate it is a good idea first of all to chat to Fr. Chris about it and he can put you in contact with the Diocesan Vocations Director.