To understand the ministry of deacon one must understand that the Gospels indicate that Jesus came to serve, not to be served, and this service model made an impression upon the early communities of Christianity. Service, and not power, affected the ways in which early communities began to designate certain titles for specific ministries. From the Acts of the Apostles, to the letters of Paul, and the pastoral epistles it seems the early communities had certain expectations that evolved over time for the ministries of bishop, priest, and deacon. A deacon was to be a good husband and father, their word must be trusted; they should not be money-oriented, solid in faith. They were to love their spouses and be models of faithful marriage.
Early Church Fathers such as Irenaeus of Lyons, Polycarp, and Justin all mention a ministry of deacon which seemed to work closely with the bishop. The description of what deacon tasks were is minimal but evidence seems to point toward communion to the homebound, overseeing the assistance to the widows and poor, among other things. Liturgically, the task of deacon evolved as well, and it seems they helped with baptisms, proclaimed the Gospel, may have presented the gifts at offertory, etc. Once again this may have looked different from location to location.
While some early texts imply some women involved in this ministry it is challenging to say with any certitude that the universal church recognized a woman deacon ministry. Also, as time evolved, and circumstances changed, the ministry of deacon became a transitional vocation to the priesthood. While the permanent diaconate never really left the Church Vatican II renewed this ministry and recognized the need for formation. Trying to capture the early notions of the early Christian communities, the Vatican II theologians wanted to verify the dignity of service by focusing on Jesus as Servant.
The orders of bishop, priest, and deacon are continuing to be discussed and their relationships with one another studied. Permanent Deacons are part of the clergy and are ordained by a Bishop to embody service to the Universal Church. They work in cooperation with bishops, priests, and the lay faithful to further the Good News of Jesus Christ to the world. The formation and life of a deacon requires commitment, and if they are married, to be good examples of the Sacrament of Marriage. Their tasks which range from liturgical duties to justice and works of charity are meant to inspire all the baptized to do the work of service that Christ commanded.