John 6:57

(Hom. xlvi) And because I live, it is manifest that he will live also: As the living Father hath sent Me, and I lice by the Father, even so he that eateth Me, even he shall live by Me. (Aug. de Verb. Dom. [Nic.]). As if He said, As the Father liveth, so do I live; adding, lest you should think Him unbegotten, By the Father, meaning that He has His source in the Father. He that eateth Me, even he shall live by Me; the life here meant is not life simply, but the justified life: for even unbelievers live, who never eat of that flesh at all. Nor is it of the general resurrection He speaks, (for all will rise again,) but of the resurrection to glory, and reward.

"As the living Father hath sent me," saith He, "and I live by the Father; so he that eateth me, even he shall live by me." He says not: As I eat the Father, and live by the Father; so he that eateth 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." 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,-whilst 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 hath sent me, and I live by the Father; so he that eateth 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, liveth 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 eateth 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.

(Tr. xxvi. s. 19) He saith not, As I eat the Father, and live by the Father, so he that eateth Me, even he shall live by Me. For the Son does not grow better by partaking of the Father, as we do by partaking of the Son, i. e. of His one body and blood, which this eating and drinking signifies. So that His saying, I live by the Father, because He is from Him, must not be understood as detracting from His equality. Nor do the words, Even he that eateth Me, the same shall live by Me, give us the equality that He has. He does not equalize, but only mediates between God and man. If, however, we understand the words, I live by the Father, in the sense of those below, My Father is greater than I, (c. 14:28) then it is as if He said, That I live by the Father, i. e. refer my life to Him, as my superior, my humiliation in my incarnation is the cause; but He who lives by Me, lives by Me by virtue of partaking of My flesh.

"He that eateth My flesh, dwelleth in Me." This He said, showing that such an one is blended with Him. Now what follows seems unconnected, unless we enquire into the sense; for, saith some one, after saying, "He that eateth My flesh, dwelleth in Me," what kind of a consequence is it to add, "As the living Father hath sent Me, and I live by the Father"? Yet the words harmonize perfectly. For since He continually spake of "eternal life," to prove this point He introduceth the expression, "dwelleth in Me"; for "if he dwelleth in Me, and I live, it is plain that he will live also." Then He saith, "As the living Father hath sent Me." This is an expression of comparison and resemblance, and its meaning is of this kind, "I live in like manner as the Father liveth." And that thou mayest not deem Him unbegotten, He immediately subjoineth, "by the Father," not by this to show that He needeth, in order to live, any power working in Him, for He said before, to remove such a suspicion, "As the Father hath life in Himself, so hath He given to the Son also to have life in Himself"; now if He needeth the working of another, it will be found that either the Father hath not given Him so to have it, and so the assertion is false, or if He hath so given it, then He will need no other one to support Him. What then means the, "By the Father"? He here merely hinteth at the cause, and what He saith is of this kind: "As the Father liveth, so I live, and he that eateth Me shall live by Me." And the "life" of which He speaketh is not life merely, but the excellent life; for that He spake not simply of life, but of that glorious and ineffable life, is clear from this. For all men "live," even unbelievers, and uninitiated, who eat not of that flesh. Seest thou that the words relate not to this life, but to that other? And what He saith is of this kind: "He that eateth My flesh, when he dieth shall not perish nor suffer punishment"; He spake not of the general resurrection, (for all alike rise again,) but concerning the special, the glorious Resurrection, that which hath a reward.

For we do not eat God simply, God being impalpable and incorporeal; nor again, the flesh of man simply, which would not profit us. But God having taken flesh into union with Himself, that flesh is quickening. Not that it has changed its own for the Divine nature; but, just as heated iron remains iron, with the action of the heat in it; so our Lord's flesh is quickening, as being the flesh of the Word of God.