For every celebration of the Eucharist, a portion of the People of God is summoned to assemble under the authority of the diocesan Bishop. The pastor, as part of the Body of Christ, leads the faithful to fulfill the Lord’s command to “do this in memory of me” (Luke 22:19). In this most sacred action of Christ and the Church, the memorial of His death and resurrection is celebrated; God is adored in spirit and in truth; the Church identifies itself with the saving sacrifice that Lord perpetuates and, nourished by His Body and Blood, looks forward in joyful hope to sharing in the supper of the Lamb in the heavenly kingdom.
This Sunday Eucharist, which gathers the local community and in which all play their proper liturgical parts, is the primary manifestation of the parish community and thus deserves particular diligent consideration and preparation. In the celebration of the Eucharist, all who are present participate according to their role and function in the Liturgy. A celebration is the work of the whole body of Christ; the ministers and other members of the congregation have a part in the action and have a contribution to make.
Liturgical roles of the Eucharistic celebration are: Presider, Deacon, Music Ministry, Reader, Extraordinary Ministers of Holy Communion (EMHC), Altar Server, and Usher/Greeters.
 See EuchMyst, no. 3a-c.
 See SC, nos. 49, 106: see GNLYC, no. 4.
 See SC, no. 28.