In terms of etymology and ancient practice, priests were generally persons who not only lead religious communities but also presided over the giving of sacrifices to God or to gods. In many traditions today this understanding is still held, such as among the Hindu and among various pagan and neo-pagan groups. Before Christian priests ever entered the historical landscape Judaism also held its own class of priests, who would preside over the presentation of sacrifices to God at the Temple in Jerusalem. Since the destruction of the Temple the Jewish priesthood has disappeared and now the leaders of Jewish religion are known as Rabbis or teachers.

For Christians the idea of the need for sacrifices to be made to God is an idea that is now made redundant by Jesus Christ. Christ in dying on the cross made the ultimate sacrifice, a sacrifice that man cannot ever hope to achieve despite his best attempts. So what, then, is the purpose of Christian priests?

In the Book of Hebrews the author speaks of Christ as the ultimate sacrifice, and differentiates between the priesthood of Christ and the priesthood of the Levites, that Israelite tribe that had served as the leaders of Israelite religion since the days of Moses. The author of Hebrews speaks of the priesthood of Melchizedek, priesthood far surpassing the Levite priesthood and of which Christ himself is the ultimate Priest.

In many of the traditions of the early church Christian priests were seen as sharing in the priesthood of Christ. As the Roman Catholic Church developed these ideas became ever stronger and Christian priests were seen as sharing in the priesthood whose head was Jesus. The leadership of the tradition of Eucharist was seen as the most important part of the role that Christian priests play, overseeing this remembrance of the ultimate sacrifice of Jesus.

Over the centuries the Christian church eventually began to break apart along lines of east and west. Ultimately this would lead to western Christian priests as well as eastern Christian priests. This geographic split was centered upon two communities: Rome, where the Apostles Peter and Paul died and what was once the primary center of the Roman Empire, and Byzantium now Constantinople, the capital of the Emperor Constantine.

Although grounded in the same tradition many of the traditions and rituals of Christianity began to take different forms among the western and eastern Christian priests. The western tradition would become what we now call the Roman Catholic Church, while the eastern tradition would lead to the various Orthodox churches such as Eastern Orthodox, Greek Orthodox and Russian Orthodox.

In the Protestant tradition which opposed much of the corruption and theology that had developed in the Catholic Church throughout the Middle Ages, the idea of Christian priests is for the most part completely rejected. Typically church leaders are referred to as pastors or some other term that does not have the ancient connotations of the word priest. In most Protestant traditions the only true Priest is seen as the Lord Jesus Christ and it is not a title that man should take upon himself.