One finds in the synoptic Gospels of the Christian Bible a certain narrative generally referred to as “the last supper,” so called because it was the final time Jesus would have a meal with his disciples prior to the crucifixion.
During this Passover feast, Christ and the twelve partook of unleavened bread and wine, according to the accounts recorded in Matthew 26, Mark 14, and Luke 28. In each instance Jesus told his followers regarding the bread, to take and eat it as it was “his body.” Also to drink the wine from the cup as it was “his blood.”
Because certain words, for instance, “like” or “as,” which would normally indicate a simile or metaphor was in view, are missing from the passages, the conclusion has been made by many that the elements of bread and wine literally change substantively or transubstantiate, as the Church of Rome calls it, into the actual flesh and blood of the Savior. (Paragraph 1376 of the Catechism of the Catholic Church)
Conversely, born of the Reformation, is the understanding that the bread and wine are consubstantial, meaning they symbolize the body and blood of Jesus. In either case, the Lord’s Supper or Communion, as it’s come to be called – the term “Eucharist” is used in Church of Rome theology – is done in remembrance of Jesus Christ, his passion leading up to and including the agony of the cross, and the new life given to all who are baptized into his death and resurrection.
Many Catholics advocate the idea that one cannot have a “genuine encounter” with Christ unless one receives the elements in a worthy manner, which basically means to them that only Catholics can truly be Christians and take communion. In their view, it’s not ONLY the blood of Christ that saves, but adherence to the practices of the Church of Rome, all its rituals and sacraments.
Perhaps that is the extreme and not necessarily applicable to the manner in which all Catholics believe, but it is very didactically espoused by many Church of Rome members. One might reasonably call attention to the literalist, transubstantiation proponents that the Bible still referred to the elements as bread and wine thereafter. Moreover one might ponder why the disciples didn’t just take and eat his flesh right on the spot and wash it down with a chalice of his blood, if that was required.
In addition to there being not a shred of biblical evidence that the bread and wine actually became flesh and blood, there is the conundrum of the clear prohibition on cannibalism as described in chapter 17 of Leviticus.
For those who apply this sort of wooden literalism to the scriptures, one would have to ask them why they haven’t sold every possession and given the proceeds to the poor (Mark 10:21), or why they haven’t plucked out their right eye, since all have looked at others with lust (Matthew 5:28, 29), or why they haven’t hacked off their offensive right hands (Matthew 5:30)?
If one applies the same thinking to other verses in the Bible that they do to the Lord’s Supper passages, one ends up with a book that advocates all manner of abysmal practices.
Fact is Jesus often spoke of things in a spiritual sense and other times in a very direct and straightforward manner. The key is to studiously peruse the way God’s revelation consistently uses words and phrases and from there develop a sound discipline. Elsewise one shall be tossed to and fro, and carried about with every wind of doctrine, by the sleight of men, and cunning craftiness, whereby they lie in wait to deceive. (Ephesians 4:14)
For more in depth information on the subject see: