Yeah, but in Augustine’s next tract, where he actualy addresses the verse in question (Jn 6:53 no Eucharist = no life within) he says that the unity of the body and blood of Christ is prepared in the Sacrament on the Lord’s table.
Tractate 26 (John 6:41-59)
15. …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.
Which totaly sounds like a Catholic answer:
Q: What are you eating? Bread and wine?
A: I’m eating the unity of the body and blood of Christ: the holy Church, the saints, the believers that was prepared in a sacrament on the Lord’s table.
Q: You seriously believe this sacrament stuff?
A: If you eat the Eucharist unworthily – you will be destroyed!!