Holy Orders is the sacrament through which men receive from God the grace to perform the sacred duties Christ entrusted to His Church.

The Twelve Apostles were the first priests and bishops of the Church. Ordination to the priesthood and diaconate involve the laying on of hands and invocation of the Holy Spirit.

Priests are ordained to be "configured to Christ," meaning that they preach, teach, and administer the sacraments of the church in the person of Christ. Only a priest can offer the Eucharist, confer Christ's absolution, and anoint the dying. 

In the early Church, the order of Deacon was created to assist the priest in service to the Christian community (Acts 6:2-6.) Today, deacons help the priest at the celebration of Mass, in the baptism of children, in the witnessing of marriage, and in the celebration of funerals. The permanent diaconate is often comprised of married men.