Octave Day of the Feast of Corpus Christi

From St. Augustine's Tractates on the Gospel of John

13."I am the living bread, which came down from heaven." For that reason "living," because I came down from heaven. The manna also came down from heaven; but the manna was only a shadow, this is the truth. "If any man eat of this bread, he shall live for ever: and the bread that I will give is my flesh, for the life of the world." When did flesh comprehend this flesh which He called bread? That is called flesh which flesh does not comprehend, and for that reason all the more flesh does not comprehend it, that it is called flesh. For they were terrified at this: they said it was too much for them; they thought it impossible. "Is my flesh,"says He, "for the life of the world."Believers know the body of Christ, if they neglect not to be the body of Christ. Let them become the body of Christ, if they wish to live by the Spirit of Christ. None lives by the Spirit of Christ but the body of Christ. Understand, my brethren, what I mean to say. You are a man; you have both a spirit and a body. I call that a spirit which is called the soul; that whereby it consists that you are a man, for thou consist of soul and body. And so you have an invisible spirit and a visible body. Tell me which lives of the other: does your spirit live of your body, or your body of your spirit? Every man that lives can answer; and he that cannot answer this, I know not whether he lives: what does every man that lives answer? My body, of course, lives by my spirit. Would you then also live by the Spirit of Christ. Be in the body of Christ. For surely my body does not live by your spirit. My body lives by my spirit, and your body by your spirit. The body of Christ cannot live but by the Spirit of Christ. It is for this that the Apostle Paul, expounding this bread, says: "One bread,"says he, "we being many are one body." (1 Corinthians 10:17) O mystery of piety! O sign of unity! O bond of charity! He that would live has where to live, has whence to live. Let him draw near, let him believe; let him be embodied, that he may be made to live. Let him not shrink from the compact of members; let him not be a rotten member that deserves to be cut off; let him not be a deformed member whereof to be ashamed; let him be a fair, fit, and sound member; let him cleave to the body, live for God by God: now let him labor on earth, that hereafter he may reign in heaven.
14. The Jews, therefore, strove among themselves, saying, "How can this man give us his flesh to eat?"They strove, and that among themselves, since they understood not, neither wished to take the bread of concord: "for they who eat such bread do not strive with one another; for we being many are one bread, one body."And by this bread, "God makes people of one sort to dwell in a house."
15. But that which they ask, while striving among themselves, namely, how the Lord can give His flesh to be eaten, they do not immediately hear: but further it is said to them, "-->Verily, verily, I say unto you, except ye eat the flesh of the Son of man, and drink His blood, you will have no life in you."How, indeed, it may be eaten, and what may be the mode of eating this bread, you are ignorant of; nevertheless, "except ye eat the flesh of the Son of man, and drink His blood, you will not have life in you."He spoke these words, not certainly to corpses, but to living men. Whereupon, lest they, understanding it to mean this life, should strive about this thing also, He going on added, "Whoso eats my flesh, and drinks my blood, has eternal life." Wherefore, he that eats not this bread, nor drinks this blood, has not this life; for men can have temporal life without that, but they can noways have eternal life. He then that eats not His flesh, nor drinks His blood, has no life in him; and he that eats His flesh, and drinks His blood, has life. This epithet, eternal, which He used, answers to both. It is not so in the case of that food which we take for the purpose of sustaining this temporal life. For he who will not take it shall not live, nor yet shall he who will take it live. For very many, even who have taken it, die; it may be by old age, or by disease, or by some other casualty. But in this food and drink, that is, in the body and blood of the Lord, it is not so. For both he that does not take it has no life, and he that does take it has life, and that indeed eternal life. And thus He would have this meat and drink to be understood as meaning the fellowship of His own body and members, which is the holy Church in his predestinated, and called, and justified, and glorified saints and believers. Of these, the first is already effected, namely, predestination; the second and third, that is, the vocation and justification, have taken place, are taking place, and will take place; but the fourth, namely, the glorifying, is at present in hope; but a thing future in realization. The sacrament of this thing, namely, of the unity of the body and blood of Christ, is prepared on the Lord's table in some places daily, in some places at certain intervals of days, and from the Lord's table it is taken, by some to life, by some to destruction: but the thing itself, of which it is the sacrament, is for every man to life, for no man to destruction, whosoever shall have been a partaker thereof.
16. But lest they should suppose that eternal life was promised in this meat and drink in such manner that they who should take it should not even now die in the body, He condescended to meet this thought; for when He had said, "He that eats my flesh, and drinks my blood, has eternal life,"He forthwith subjoined, "and I will raise him up on the last day."That meanwhile, according to the Spirit, he may have eternal life in that rest into which the spirits of the saints are received; but as to the body, he shall not be defrauded of its eternal life, but, on the contrary, he shall have it in the resurrection of the dead at the last day.
17. "For my flesh,"says He, "is meat indeed, and my blood is drink indeed."For while by meat and drink men seek to attain to this, neither to hunger nor thirst, there is nothing that truly affords this, except this meat and drink, which does render them by whom it is taken immortal and incorruptible; that is, the very fellowship of the saints, where will be peace and unity, full and perfect. Therefore, indeed, it is, even as men of God understood this before us, that our Lord Jesus Christ has pointed our minds to His body and blood in those things, which from being many are reduced to some one thing. For a unity is formed by many grains forming together; and another unity is effected by the clustering together of many berries.
18. In a word, He now explains how that which He speaks of comes to pass, and what it is to eat His body and to drink His blood. "He that eats my flesh, and drinks my blood, dwells in me, and I in him."This it is, therefore, for a man to eat that meat and to drink that drink, to dwell in Christ, and to have Christ dwelling in him. Consequently, he that dwells not in Christ, and in whom Christ dwells not, doubtless neither eats His flesh [spiritually] nor drinks His blood [although he may press the sacrament of the body and blood of Christ carnally and visibly with his teeth], but rather does he eat and drink the sacrament of so great a thing to his own judgment, because he, being unclean, has presumed to come to the sacraments of Christ, which no man takes worthily except he that is pure: of such it is said, "Blessed are the pure in heart, for they shall see God."Matthew 5:8
19. "As the living Father has sent me,"says He, "and I live by the Father; so he that eats me, even he shall live by me."--> He says not: As I eat the Father, and live by the Father; so he that eats me, the same shall live by me. For the Son, who was begotten equal, does not become better by participation of the Father; just as we are made better by participation of the Son, through the unity of His body and blood, which thing that eating and drinking signifies. We live then by Him, by eating Him; that is, by receiving Himself as the eternal life, which we did not have from ourselves. Himself, however, lives by the Father, being sent by Him, because "He emptied Himself, being made obedient even unto the death of the cross."Philippians 2:8 For if we take this declaration, "I live by the Father,"according to that which He says in another place, "The Father is greater than I;"just as we, too, live by Him who is greater than we; this results from His being sent. The sending is in fact the emptying of Himself, and His taking upon Him the form of a servant: and this is rightly understood, while also the Son's equality of nature with the Father is preserved. For the Father is greater than the Son as man, but He has the Son as God equal,—while the same is both God and man, Son of God and Son of man, one Christ Jesus. To this effect, if these words are rightly understood, He spoke thus: "As the living Father has sent me, and I live by the Father; so he that eats me, even he shall live by me:"just as if He were to say, My emptying of myself (in that He sent me) effected that I should live by the Father; that is, should refer my life to Him as the greater; but that any should live by me is effected by that participation in which he eats me. Therefore, I being humbled, do live by the Father, man being raised up, lives by me. But if it was said, "I live by the Father,"so as to mean, that He is of the Father, not the Father of Him, it was said without detriment to His equality. And yet further, by saying, "And he that eats me, even he shall live by me,"He did not signify that His own equality was the same as our equality, but He thereby showed the grace of the Mediator.
20. "This is the bread that comes down from heaven;"that by eating it we may live, since we cannot have eternal life from ourselves. "Not,"says He, "as your fathers did eat manna, and are dead: he that eats this bread shall live forever."That those fathers are dead, He would have to be understood as meaning, that they do not live forever. For even they who eat Christ shall certainly die temporally; but they live forever, because Christ is eternal life.