Irenaeus lived in three major regions of Christianity (Smyrna, Rome, and Lyons) throughout his lifetime, so he is a testament to what the universal Church taught and believed in the second century.
Key Ideas, Good Facts and Passages to Memorize:
Irenaeus considered the Real Presence of Christ to be so beyond doubt that he used it to argue against other heresies. Irenaeus believed the Eucharist to be physically the body and blood of Jesus in the same way that his fleshly body was physically his body.
“But our opinion is in accordance with the Eucharist, and the Eucharist in turn establishes our opinion” (Against Heresies, IV, 18, 5).
“He has acknowledged the cup (which is a part of the creation) as His own blood, from which He bedews our blood; and the bread (also a part of the creation) He has established as His own body, from which He gives increase to our bodies” (Against Heresies, V, 2, 2).
The bread and wine “having received the Word of God, becomes the Eucharist, which is the body and blood of Christ” (Against Heresies, V, 2, 3).
Effective Questions to Ask When Discussing the Real Presence:
If some of the Christian communities that Irenaeus visited didn’t believe in the Eucharist, why did Irenaeus consider it something so undoubtable that he used it to argue against other heresies? If Irenaeus didn’t believe that the Eucharist was really the body and blood of Jesus, how do you make his arguments in these texts make sense? Irenaeus was a disciple of Polycarp who was a disciple of John the Apostle. Is it reasonable that Jesus’s teachings on the Eucharist, from the bread of life discourse and the Last Supper, were already so corrupted by the time they got to St. Irenaeus that he did not understand what the Eucharist actually was?
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