At the Last Supper, held with His disciples prior to His crucifixion and resurrection, the Lord Christ instituted the Sacrament of the Eucharist (a Greek term meaning “thanksgiving”). This sacrament is celebrated within the Church during every Divine Liturgy, where the faithful partake of Christ’s Body and Blood to be united with Him; Christ is truly present in the Eucharist, and participation in it grants eternal life.
The concept of union was central to the Church Fathers when addressing the Eucharist, signifying both union with Christ and the unity of the faithful with one another. For instance, Saint Ignatius of Antioch (d. 107) exhorted the people of Philadelphia (in modern-day Turkey), saying: “Strive to partake of one Eucharist, for there is but one Body of our Lord Jesus Christ, one cup for the unity of His Blood, one altar, and one bishop together with his presbyters and deacons.” Hence, the Orthodox Church emphasizes celebrating only one Divine Liturgy per day, as the single parish community is called to be one, rather than a collection of fragmented groups.
The Eucharist is the Body of Christ—not a dead body, but a living one. As soon as our bodies partake of it in the Eucharist, they receive life and are united with incorruptibility.
Saint Cyril of Jerusalem (+386) says: “Before the invocation of the Holy Trinity upon them, the bread and wine were merely ordinary bread and wine. But once this invocation and supplication took place, the bread and wine were transformed into the Body and Blood of Christ.”
