Kretzmann's Popular Commentary
John 6:59
These things said He in the synagogue, as He taught in Capernaum.
Although Jesus had been careful to explain His figure sufficiently that all might have understood Him, yet the understanding was lacking in the greater number of His hearers. There was a division, a dispute, among them. They differed in their judgment of Him. Some severely denounced Him as insane, others suggested that there might be some truth in His words. But they all thought of physical, sensual eating and partaking. Jesus therefore summarizes the lessons which He wishes to convey once more. He tells them that it is indeed essential for everyone that wishes to have eternal life that he eat His flesh and drink His blood. It is necessary for every believer to receive Jesus altogether by faith, in His full work of atonement, active and passive obedience, shedding of blood, and all. By doing so, the believer has the assurance of eternal life and will rise on the last day to see the consummation of all glories. In this way the body of Christ is the true food, and His blood the true drink. In this way, also, the wonderful union of Christ and the believers in Him is brought about. They receive Christ spiritually and are most intimately and inseparably united with Him. They dwell in the Savior and the Savior in them. And this wonderful union extends still farther. The living Father has sent the Son; the Son, in that mysterious relationship which His eternal Sonship expresses, lives through the Father; and so both persons of the Godhead are the Fountainhead of life and give to the believer the fullness of perfect life, which will last throughout eternity. He that believes on the Son places his trust, first of all, in the human nature, in the man Jesus Christ that died for the sins of the whole world. But thereby he also accepts and clings to the divine nature, to the entire, Godhead and all His gifts. Thus the human nature of Christ is like a bridge between God and man. He that believes in Jesus the Savior has the entire Christ in himself, according to both, divine and human natures, true God and man. That the Jews put their trust in the mere historical fact of the manna in the wilderness, believing that in some way they were partakers of the benefits that came upon their fathers at that time, was altogether foolish. Only by faith in Christ, the living Bread from heaven, can eternal life be obtained. John remarks, with his usual exact specification of time and place, that this wonderful sermon was held in Capernaum, in the synagogue. It is immaterial whether it was on a Sabbath or on one of the week-days when there were services, Monday or Thursday. Jesus gave a clear and unmistakable testimony concerning Himself, full of glorious comfort to the believer.
"The Flesh of the Son of Man"
Since the time of the Reformation, the Reformed sects, almost without exception, have understood the passage John 6:51 of the Lord's Supper, in order to bolster up their false doctrine concerning a mere spiritual eating and drinking in the Eucharist. Their standpoint may be summarized in one sentence: "Even if Christ does give us His flesh in the Holy Supper, it still has no value; for everything depends upon the spirit."
That this position is untenable is evident from the very words. For if these words of the Lord did treat of the Lord's Supper, long before this Sacrament was instituted and known, then the real presence would certainly be taught here, a fact which all the followers of Zwingli would repudiate with the greatest severity. But the words in their connection cannot be understood but of the faith which accepts Jesus and all His works and merits. And the contrast between flesh and spirit in verse 63 has nothing whatever to do with the Eucharist, since it opposes the work of the Spirit of God to the unprofitable working of the natural condition of man. "Since, then, this is true and incontrovertible that flesh, where it is contrasted to spirit, cannot mean the body of Christ, but the old Adam, born of the flesh, it is certain, also, that here, John 6:63, the words 'Flesh profited nothing' cannot be understood of the body of Christ, because Christ there places flesh in opposition to spirit. For thus His words Bound clearly: It is the spirit that quickeneth, the flesh profited nothing; the words that I speak unto you, they are spirit, and they are life. There you see plainly that He distinguishes between flesh and spirit and places the former in opposition to the latter. For He evidently teaches that life and spirit is in His words, and not in the flesh. Of the flesh He affirms that it is unprofitable. And how can it be profitable, if neither life nor spirit is found therein? If there is no life nor spirit therein, then there must be only death and sin therein. Which heretic has now been so desperate (excepting the Jews) as to understand this of the flesh of Christ? Now let the enthusiasts try themselves out; let us see what they can do; they have boasted that this was an iron wall and the certain truth; if they can make good their boast, I should like to see it. " "The eating and drinking is nothing but believing in the Lord Jesus Christ, who gave His flesh and blood for me, in order to deliver me from sin, death, devil, hell, and all misfortune. Such faith can never exist without life; therefore, he that believes must live and be just, as Habakkuk says, chap. 2:4: The just shall live by faith. Therefore the eating is done with the heart and not with the mouth. The eating with the heart does not deceive, but the eating with the mouth does; the eating with the mouth will have an end, the other lasts eternally without interruption. For the heart is nourished and fed by faith in Christ. There you see plainly that these words are not to be understood of the Sacrament of the Altar. Therefore to eat the flesh of the Son of God and to drink His blood, as has been said, is nothing else than that I believe His flesh was given for me and His blood was shed for me, and that for my sake He conquered sin, death, devil, hell, and all misfortune. Out of such faith there results a great and mighty confidence in Him and a scorn and bold courage against all misfortune, that I may henceforth fear nothing, neither sin nor death nor devil nor hell, since I know that my Lord cast them under His feet and conquered them for my sake."