The Third Week of Easter, except for Tuesday April 25, focuses upon Chapter 6 of Saint John’s Gospel or the Bread of Life Discourse. Catholics believe that once the priest consecrates the bread and the wine at Mass, the Eucharist is truly Jesus Christ in the flesh and in the spirit. The priest’s words of institution (the consecration in the Eucharistic prayer) have the spiritual effect of those elements retaining the appearance of bread and wine while God performs the miracle of transubstantiation. Thus, in receiving Communion, we are consuming the true Body and Blood of Jesus, just as Christ taught at the Last Supper and just as St. Paul declared in his first Letter to the Corinthians 10 and 11.
Consider what is arguably the most compelling fact that is found in Saturday’s Gospel passage (Jn 6:66) when the Lord’s own disciples reject Him and walk away from Him, refusing to believe in Him any longer. Christ had consistently and frequently taught everything we see in John 6 except the eating of his flesh and drinking of his blood. There are two unique facts in John 6. It is the first mention of the need to consume Christ’s flesh and blood, and it is the only time we see followers of Christ say that a teaching is too hard for them to accept and, then, many disciples walk away. There are other times when non-believers walk away from Jesus, but here those who do so are His actual followers. There must be a reason for this, and a reason that the Church Fathers pointed to since apostolic times was the eating of Christ’s flesh and the drinking of Christ’s blood as the reason the disciples called the teaching too hard and walked away.
Catholics note clear Eucharistic teaching and belief of the Last Supper accounts, where Christ gave us the words that Catholic priests use to consecrate the Body and Blood at every Mass. We also see St. Paul’s clear Eucharistic belief and teachings in 1 Corinthians 10:16: “Is not the cup of blessing which we bless a sharing in the blood of Christ? Is not the bread which we break a sharing in the body of Christ?” Paul comes back to the Eucharist in 1 Corinthians 11:23-29: “Therefore whoever eats the bread or drinks the cup of the Lord in an unworthy manner shall be guilty of the body and the blood of the Lord.” As you can see, Paul took John 6 literally (both the physical and spiritual aspects). And Paul tells us John 6 is not simply spiritual, symbolic, or figurative. For St. Paul, the body and blood of John 6 is the very same as the body and blood of the Eucharist.
That bread which you see on the altar, having been sanctified by the word of God, is the body of Christ. That chalice, or rather, what is in that chalice, having been sanctified by the word of God, is the blood of Christ. Through that bread and wine the Lord Christ willed to commend his body and blood, which he poured out for us unto the forgiveness of sins (Sermons 227).
Saint Ignatius of Antioch
I desire the bread of God, the heavenly bread, the bread of life, which is the flesh of Jesus Christ, the Son of God, who became afterward of the seed of David and Abraham; and I desire the drink of God, namely his blood, which is incorruptible love and eternal life.
Saint Justin Martyr
For not as common bread nor common drink do we receive these; but since Jesus Christ our Savior was made incarnate by the word of God and had both flesh and blood for our salvation, so too, as we have been taught, the food which has been made into the Eucharist by the eucharistic prayer set down by him, and by the change of which our blood and flesh is nourished, is both the flesh and the blood of that incarnated Jesus.