The ministry of a deacon is similar to but different from that of a priest or bishop. A deacon is ordained and missioned by Christ through the bishop to minister to the needy and the poor and to be a minister of Word and Sacrament, working in obedience to his bishop and in close fraternal cooperation with priests. While all Christians are called to serve others, the deacon is an official sign of this service and he solemnly promises to be a living example of such service for others.
Yes. Through Holy Orders, the deacon acquires a special relationship to the bishop. Though surely "his own man" - by reason of his place in the hierarchy - tradition refers to him as "the bishop's man ... the bishop's ears and eyes." His ministry of charity, word, and sacrament enables the Church to be a credible sign of the Servant Christ in the world.
Men who are to be ordained priests are ordained deacons prior to priesthood. These men are sometimes referred to as "transitional" deacons, because they are in the process of transition into priesthood. Men who are ordained deacons and remain in that state are sometimes referred to as "permanent" deacons. Both transitional and permanent deacons share in the Order of Deacon.
Married men can become deacons. Single men who are ordained deacons take a promise of celibacy, similar to the priest's promise of celibacy, and may not marry once they are ordained. If married, the deacon candidate should be in a stable marriage for a number or years and have the expressed consent and support of his wife. His children should also be of such an age and adjustment as not to be unduly affected by their father's pursuit of a life that involves special apostolic commitments.
This is a complex question and certainly deserves more than a short answer. But in short, the priest models his life after Christ the Priest; the deacon models his life after Christ the Deacon. Each shares uniquely in the ministry of Christ to His people, the Church. Sacramentally, a deacon is an ordinary minister of Baptism, and can serve as the official witness to marriage. A deacon may also read the Gospel and preach at Mass. Deacons are also ordinary ministers of communion. Only a priest can celebrate Mass, offer absolution of sins in the Sacrament of Penance, and Anoint the Sick.
The deacon reaches out to the poor, the sick, the elderly, the divorced, the imprisoned and others in order to first address their human needs. He does charitable, administrative and welfare work in the name of the Church. He organizes, leads and supports lay ministry. He assists in marriage and baptismal preparation as well as being involved in social ministries at every level. Having thus been identified in the role of servant, he may then become more effectively a liturgical minister to proclaim the Gospel and preach, to assist at the Eucharist, celebrate Eucharistic devotions, to baptize and witness marriages, to administer sacramentals and to bury the dead.
The deacon is called personally and ecclesially to serve after the manner of Jesus. He is first and foremost a Christian man in his usual employment and lifestyle, trained and formed by additional study and prayer for a special ministry to the community as an ordained minister. Each diocesan diaconate office sets its own criteria for suitable deacon candidates. Here are some of the more common considerations:
The Order of Deacons was instituted by the Apostles. It was restored as a permanent and public ministry in the Roman Church as a result of a decision made by the bishops at the Second Vatican Council. The restoration of the permanent diaconate was authorized in the Canada and the United States in 1968.
The aims of the diaconate are to enrich and strengthen the works of service being performed by the Church, to enlist a new group of devout and competent married and single men in the active ministry of the Church, and to aid in extending needed charitable and liturgical service to the faithful. Wives of deacons assist in many of these areas.