The deacon is a member of the first, and foundational, tier of the hierarchy of Holy Orders. Every bishop is first a priest; every priest is first a deacon. Thus, the charism of the deacon is common to all of the clergy, and is the foundation upon which the priestly and episcopal (bishop) charisms are built. At times, many of the popes and bishops have worn the deacon’s garment, the dalmatic, under their other vestments at Mass to remind themselves of the primacy of their diaconal charism.
From very early times, deacons were regarded as having a special relationship to bishops. One early Christian document, the Didascalia Apostolorum, says a deacon is “the eyes and ears, the mouth, heart, and soul of the bishop.” Thus, the hierarchy of ordained ministry does not so much run from the top down — bishop to priest to deacon — as form a triangle, with priests and deacons in a complementary relationship to the bishop.
It is essential to see deacons in the context of three general areas of service: the ministry of the Word, the ministry of the liturgy, and the ministry of charity. In all these areas, the deacon as servant leader helps God’s people take what they receive in the Church out into the world where it may bear abundant fruit.