Throughout the writings of the New Testament, there appear different understandings of leadership, and who should be leaders. Clearly the Apostles appear as the first source of leadership for the emerging Church. However, following upon their death, the question emerges as to who would replace them in leading the Christian community. In the communities founded by St. Paul a structured leadership emerges. While in other communities a charismatic structure appeared. These differing structures were held together with a commitment of unity with the Church.

By the beginning of the third century a ritual for the ordination of a Bishop appears in the writings attributed to St. Hippolytus. The ritual speaks of all the community being present at the ceremony presided over by a bishop who will lay hands on the candidate to be Bishop. His document also speaks of the ordination of Priests and Deacons. He also refers to other offices within the community: widows, readers, virgins, subdeacon and healers. Over time some of these offices disappears and others move from being an office for a layperson to being included in the clerics.

Following the liturgical reform of Vatican II, Pope Paul VI undertook the revision of the rituals for the ordination of Bishops, Priests and Deacons. He also saw to the revision of other offices and extended them to the laity, particularly acolyte and lector. He also left open the possibility of other ministries being established by the Conferences of Bishops in response the local pastoral needs. Many ministries have appeared but have not been established as formal ministries, for example catechists.
Thus over centuries there has emerged an ordered structure for the Church, but always built upon the vision of the one Body of Christ. Some are called to ordained service in the Church: today we name them as Bishop, Priest, Deacon. The Bishop is ordained to oversee a particular territory of the Church, which is called the Diocese. As servant to the bishop, the Priest usually serves a parish within the Diocese by presiding at Eucharist and the other sacraments, except Ordination which is reserved to the Bishop. The Deacon is set aside for Word and Service of the Poor but would not celebrate the sacraments.

It is through their faithful service of all her ordained ministers that the Church continues as the Body of Christ to the ends of the earth to be the sign of God’s presence in the world.