The Major Holy Orders are
The office of bishop. The Apostles themselves appointed the first bishops in the Church. Even before Pentecost, after Judas had turned traitor, Peter declared in applying Psalm 109:8,
“His bishopric let another take” (Acts 1:20, KJV)
The word “bishopric” refers to the function of a bishop and its use obviously indicates the “job description” of bishops as being that of the Apostles in their own area (later, diocese). Some have mistakenly argued that the office of bishop was a later “human” invention. Quite to the contrary, the Apostles appointed bishops to succeed them to oversee the Church in each locality. Occasionally, the objection is still heard that the offices of bishop and presbyter were originally identical. It is true the terms are sometimes used interchangeably in the New Testament while the Apostles were present, but it was the understanding of the entire early Church that, with the death of the Apostles, the offices of bishop and presbyter were distinct. Ignatius of Antioch, consecrated bishop by A.D. 70 in the church from which Paul and Barnabas had been sent out, writes just after the turn of the century that bishops appointed by the Apostles, surrounded by their presbyters, were everywhere in the Church.
The office of presbyter. Elders or presbyters are mentioned very early in the life of the Church in the Book of Acts and the Epistles. It is evident that in each place a Christian community developed, elders were appointed by the Apostles to pastor the people. As time passed, presbyters were referred to in the short form of the word as “prests”, then as “priests”, in full view of the fact that the Old Covenant priesthood had been fulfilled in Christ and that the Church is corporately a priesthood of believers. The priest was not understood as an intermediary between God and the people, nor as a dispenser of grace. It was the role of the priest to be the presence of Christ in the Christian community, laying down his life for his flock, as did Christ. And in the very capacity of being the presence of the Chief Shepherd, Jesus Christ, the priest was to shepherd the flock of God.
The office of deacon. The third order or office in the government of the New Testament Church was that of deacon. At first the Apostles fulfilled this office themselves. But with the rapid growth of the Church, seven initial deacons were selected, as reported in Acts 6, to help carry the responsibility of service to those in need. It was one of these deacons, Saint Stephen, who became the first martyr of the Church, and his courageous witness has inspired a multitude to follow his example in faith, witness and service. Through the centuries, the deacons have not only served the material needs of the Church, but have held a key role in the liturgical life of the Church as well, serving the most visible and vocal portions of Christian worship with honor and holiness. Often called “the eyes and ears of the bishop”, many deacons have become priests and ultimately entered the episcopal office.