Priestly service is the continuation of the apostolic service of the Church. The essence of priesthood or the Holy Orders is, by using the words of Saint Paul, ‘being all to all’ – being Christ to all. The priest, ordained as such by the laying of hands during Eucharist, is the one who makes Christ present. He is the one who ‘represents’ in a very real sense of that word Christ’s care, Christ’s love and Christ’s teaching.
Wherever they founded new Church communities Apostles also ordained bishops as their successors, and the bishops would then ordain priests and deacons as assistants of their own. This is called the Church hierarchy. It has its origin in the person of Lord Jesus Christ and in the Holy Spirit who descended on the disciples at the occasion of the Pentecost. Apostles conveyed to their successors that which was conveyed to them by the Lord Himself: the same faith, the same Baptism, the same Sacraments, the same life in God and after God. Their successors conveyed to descendents of their own that which they themselves had received through the laying of hands (through the Sacrament of the Holy Orders) and this continued on and on as a ceaseless apostolic heritage, apostolic right, which is continued until today and which shall continue throughout the ages until the end of time. The priesthood serves to preach the Gospel, safeguard Orthodox faith, and perform the Sacraments. There can be no Church without its priesthood although all Christians continue the apostolic professing of Christ and His holy deeds. By performing its service Church becomes the Icon of the Head and the Body of Christ. This service is rendered by the priesthood but not without the full participation of the faithful.
There are three major ranks of Holy Orders or priesthood: deacon, presbyter and bishop. A person is introduced into one of these ranks of priesthood by ordination, i.e. by the laying of hands. There are also lesser ranks in Church hierarchy, e.g. readers and sub-deacons.