Eucharistic theology is a branch of Christian theology which treats doctrines concerning the Holy Eucharist, also commonly known as the Lord's Supper. It exists exclusively in Christianity and related religions, as others generally do not contain a Eucharistic ceremony.
In the Gospel accounts of Jesus' earthly ministry, a crowd of listeners challenges him regarding the rain of manna before he delivers the famous Bread of Life Discourse (John 6:22–59), and he describes himself as the "True Bread from Heaven". The aforementioned Bread of Life Discourse occurs in the Gospel of John, John 6:30–59. Therein, Jesus promises to give his flesh and blood, which he states will give eternal life to all who receive it. In John 6:53 (RSV), Jesus says, "Truly, truly, I say to you, unless you eat the flesh of the Son of man and drink his blood, you have no life in you"; in verses 54–55, he continues: "he who eats my flesh and drinks my blood has eternal life, and I will raise him up at the last day. For my flesh is food indeed and my blood is drink indeed."
Every year, Jews in Israel celebrated the Passover Meal, remembering and celebrating their liberation from captivity in Egypt. In the Gospel of John, Jesus is recorded as celebrating the Last Supper with his Apostles at Passover.
Saint Paul, in his First Letter to the Corinthians (1 Corinthians 11:23–26), as well as the Synoptic Gospels of Matthew (Matthew 26:26–28), Mark (Mark 14:22–24), and Luke (Luke 22:19–20), state that Jesus, in the course of the Last Supper on the night before his death, instituted the Eucharist, stating: "This is my body", and "This is my blood". For instance, Matthew recounts: "And as they were eating, Jesus took bread, and blessed it, and brake it, and gave it to the disciples, and said, Take, eat; this is my body; And he took the cup, and gave thanks, and gave it to them, saying, Drink ye all of it; For this is my blood of the new testament, which is shed for many for the remission of sins."
The Gospel of John, on the other hand, makes no mention of this. One explanation offered is that the author of the Gospel of John intended the Gospel to supplement what other evangelists had already written.
Overview
Because Jesus was a person, theology regarding the Eucharist involves consideration of the way in which the communicant's personal relationship with God is contributed to by consumption of the Eucharist. However, debates over Eucharistic theology in the West have centered on the metaphysical aspects of Jesus' presence in this ritual.
Real presence
Transubstantiation
In the substance theory of the Eucharist, the substances of the bread and wine become the substances in the body, blood, soul and divinity of Jesus; however, it is also believed that the accidents (physical traits, including chemical properties) of the bread and wine remain. This view is taught by the Roman Catholic Church, including in its Eastern Rites.
Definitive change
Eastern Orthodox Christians generally prefer not to be tied down by the specifics of the defined doctrine of transubstantiation, though there is agreement with the definition's conclusion about the real presence of Christ in the Eucharist. Eastern Orthodox Christians use the term "change" (), as in the epiclesis of the Divine Liturgy, to describe the change of the bread and wine into the actual body and blood of Jesus. (See "Objective reality, silence about technicalities", below.) The terminology of transubstantiation was adopted within the Eastern Orthodox Church by the Synod of Jerusalem (1672), although it is not recognized as having the authority of an Ecumenical Council and has been criticized for a perceived tendency toward Latinization.
Consubstantiation
Consubstantiation is the belief that "The bread retains its substance and ... Christ's glorified body comes down into the bread through the consecration and is found there together with the natural substance of the bread, without quantity but whole and complete in every part of the sacramental bread." Consubstantiation was the position of the Lollards. It is erroneously used to denote the position of the Lutheran Church (see below), who instead affirm the doctrine of sacramental union. Some Anglicans identify with this position.
