Saint Paul's Letter to the Hebrews (esp chapters 4-10) teaches us a great deal about Christ as the true priest. From this description the role of the priest in the Church today can be better understood. It is clear that Christ is the one-and-only true priest. Since Christ's priesthood lasts forever and is unchanging, he must be the model for all priests in every age and in every place. Although Christ is generally seen as Savior, Son of God, Messiah, healer, or teacher, there can be no doubt that he fulfilled the duties of a priest with his death on the cross.
The Old Testament priests were called upon to offer sacrifice for the people in the Temple. They had an important role in the Jewish community of believers who were awaiting the coming of the Messiah. Melchizedek, the greatest priest of the Old Testament, is regarded as the type or pattern of the priest in today's Church (Gn 14:17-20). But the bread and wine he offered were just the elements of sacrifice that he chose to offer. It was Christ who transformed the bread and wine into his own Body and Blood.
The principal duty of the priest has always been to offer sacrifice. In the Old Testament, the people would bring their choice animals or the first-fruits of their harvest to the Temple at certain times of the year. The priest then would offer sacrifice by killing the animal or burning the harvest offering. this action would be performed so that the people could atone for their sins and be reconciled with God. Thus the priest was the link between God and his people in the Old Testament.
Christ came to offer a sacrifice too, but his was not to offer a choice animal or the first-fruits of the harvest. He offered himself on the Cross to the Father so that all people might be reconciled with the Father. Christ was both the victim and the priest. He was the offering and also the offerer. By his death all people could be free from their sins. This was a perfect sacrifice. There can be no greater sacrifice than this: the God-man offering himself totally to the Father through his death on the Cross.
Not only was it a perfect sacrifice, it was the neverending sacrifice. It happened once on Good Friday at a place called Calvary. Now it goes on forever in eternity affecting all people. Christ by his death brought to completion all the animal and harvest sacrifices of the Old Testament. What those sacrifices lacked because of their strictly human origin Christ completed by his divine sacrifice on the Cross. In the same way, all sacrifices made by people today are completed through the action of Christ offering himself on the Cross.
HOLY ORDERS, therefore, 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 (that is Bishops), presbyterate (priests), and diaconate (deacons).
IN THE PERSON OF CHRIST THE HEAD...
In the ministerial service of the ordained minister, it is Christ himself who is present to his Church as Head of his Body, Shepherd of his flock, high priest of the redemptive sacrifice, Teacher of Truth. This is what the Church means by saying that the priest, by virtue of the sacrament of Holy Orders, acts in persona Christi Capitis.
It is the same priest, Christ Jesus, whose sacred person his minister truly represents. Now the minister, by reason of the sacerdotal consecration which he has received, it truly made like the high priest and possesses the authority to act in the power and place of the person of Christ himself (virtute ac persona ipsius Christi).
Christ is the source of all priesthood: the priest of the old law was a figure of Christ, and the priest of the new law acts in the person of Christ.
Through the ordained ministry, especially that of bishops and priests, the presence of Christ as head of the Church is made visible in the midst of the community of believers.
This presence of Christ in the minister is not to be understood as if the latter were preserved from all human weaknesses, the spirit of domination, error, even sin. the power of the Holy Spirit does not guarantee all acts of ministers in the same way.
The sacrament of Holy Orders is conferred by a Bishop, through the laying on of hands followed by a solemn prayer of consecration, asking God to grant the ordinand the graces of the Holy Spirit required for his ministry. So that he may act as a representative of Christ, Head of the Church, in his triple office of priest, prophet and king.
ROLE OF A PRIEST To live in the midst of the world with no desire for its pleasures; to be a member of every family, yet belong to none; to share all sufferings; to penetrate all secrets; to heal all wounds; to go daily from man to God to offer him their homage and petition; to return from God to men to bring them his pardon and his hope; to have a heart of iron for chastity, and a heart of flesh for charity; to teach and instruct; to pardon and console, to bless and be blessed forever! O God, what a life, and it is yours, O priest of Jesus Christ.