Tractates on the Gospel of John

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 immediately 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.