Solemnity of the Most Holy Body and Blood of Christ, John 6:51-58
 I  am the living bread that came down from heaven; whoever eats this bread  will live forever; and the bread that I will give is my flesh for the  life of the world. […] Whoever eats my flesh and drinks my blood has  eternal life. […] Whoever eats my flesh and drinks my blood remains in  me and I in him.
 Most,  though not all, Protestants wiggle and fidget as they come to the Bread  of Life Discourse in the sixth chapter of the Gospel according to St.  John; and they have good reason to be disturbed! Our Savior speaks quite  plainly of the Eucharist when he states, For my flesh is meat indeed: and my blood is drink indeed (John 6:56). 
 The  common solution for many modern Protestants (following the path set out  by Zwingli) is to call upon the words which follow toward the end of  the discourse: It is the spirit that quickeneth: the flesh profiteth nothing. The words that I have spoken to you, are spirit and life (John 6:64). Appealing to these words, which reference the spirit as opposed to the flesh, these Protestants will claim that the Bread of Life Discourse is an extended metaphor.
 There  are four reasons why our Savior’s words in John 6:26-72 cannot be  understood as an analogy or a metaphor. Among these, the second is  perhaps rather unknown. [all four reasons come from Ludwig Ott’s Fundamentals of Catholic Dogma]
 1) From the nature of the words used
 One  specially notes the realistic expressions “true” and “real” referring  to the “food” and “drink” which is our Savior’s body and blood.  Likewise, we note the concrete expressions employed to denote the  reception of this Sacrament: the Greek word commonly translated as “to  eat” is more literally “to gnaw upon” or “to chew”. 
 The bread that I will give, is my flesh, for the life of the world. […] For my flesh is meat indeed: and my blood is drink indeed (John 6:52,56).
 2) From the biblical usage of the figure “to eat one’s flesh”
 In  the language of the Bible, to eat another’s flesh or to drink his blood  in the metaphorical sense is to persecute him, to bring him to ruin and  to destroy him. Thus, if Christ tells the Jews that we all must eat his  flesh and drink his blood, and if he means this metaphorically, we  would be led to conclude (following the witness of Sacred Scripture)  that our Savior intends us to reject him.
 Consider how the metaphor of eating flesh and drinking blood functions in the Scriptures:
 Whilst  the wicked draw near against me, to eat my flesh. My enemies that  trouble me, have themselves been weakened, and have fallen. (Psalm 26:2)
 By  the wrath of the Lord of hosts the land is troubled, and the people  shall be as fuel for the fire: no man shall spare his brother. And he  shall turn to the right hand, and shall be hungry: and shall eat on the  left hand, and shall not be filled: every one shall eat the flesh of his  own arm: Manasses Ephraim, and Ephraim Manasses, and they together  shall be against Juda. (Isaiah 9:19-20)
 And I will feed thy enemies with their own flesh: and they shall be made drunk with their own blood, as with new wine. (Isaiah 49:26)
 You  that hate good, and love evil: that violently pluck off their skins  from them, and their flesh from their bones? Who have eaten the flesh of  my people, and have flayed their skin from off them: and have broken,  and chopped their bones as for the kettle, and as flesh in the midst of  the pot. (Micah 3:2-3)
 Go  to now, ye rich men, weep and howl in your miseries, which shall come  upon you. […] Your gold and silver is cankered: and the rust of them  shall be for a testimony against you, and shall eat your flesh like  fire. (James 5:1,3)
 And  the ten horns which thou sawest in the beast: these shall hate the  harlot, and shall make her desolate and naked, and shall eat her flesh,  and shall burn her with fire. (Revelation 17:16)
 3) From the reactions of the listeners
 The listeners understand Jesus to be speaking in literal truth – How can this man give us his flesh to eat?  (John 6:53) – and Jesus does not correct them, as he had done  previously in the case of misunderstandings (cf. John 3,3; 4:32; Matthew  16:6). In this case, on the contrary, he confirms their literal  acceptance of his words at the rist that his disciples and his apostles  might desert him. Indeed, our Savior is willing to test his apostles on  this point: Then Jesus said to the twelve: Will you also go away? (John 6:68)
 4) From the interpretation of the Fathers and the Magisterium
 Finally,  we can recognize that this text is not to be understood as a metaphor  from the interpretation of the Fathers, who ordinarily take the last  section of the Bread of Life Discourse as referring to the Eucharist  (e.g. St. John Chrysostom, St. Cyril of Alexander, St. Augustine, et  al.). Moreover, the interpretation of the Council of Trent confirms  this.
 The words that I have spoken to you, are spirit and life
 In  John 6:64, Jesus does not reject the literal interpretation, but only  the grossly sensual interpretation. Our Savior insists that the  Eucharist is spirit and life insofar as it gives life. For the body we receive in the Eucharist is not dead flesh, but profits us unto eternal life. 
 So  St. Augustine says, “This Flesh alone profiteth not, but let the Spirit  be joined to the Flesh, and It profiteth greatly. For if the Flesh  profiteth nothing, the Word would not have become Flesh.” The same (lib.  10, de. Civit. Dei) says, “The Flesh of itself cleanseth not, but  through the Word by which it hath been assumed.” And S. Cyril, “If the  Flesh be understood alone, it is by no means able to quicken, forasmuch  as it needs a Quickener, but because it is conjoined with the  life-giving Word, the whole is made life-giving. For the Word of God  being joined to the corruptible nature does not lose Its virtue, but the  Flesh itself is lifted up to the power of the higher nature. Therefore,  although the nature of flesh as flesh cannot quicken; still it doth  this because it hath received the whole operation of the Word.”
 Hence, we do well to pray: May the body and blood of our Lord Jesus Christ guard my soul unto everlasting life. Amen.


 

