This verse states negatively the same truths that were stated positively in verse 51. Here, however, the Son of Man is mentioned, and the necessity of drinking his blood. Commentators generally agree that blood is introduced to call to mind the eucharist, and at the same time to indicate that it is the total being of the Son of Man that gives life—in Hebrew thought “flesh and blood” were equivalent to the total person. Whatever the source of meaning of eat the flesh … drink his blood, these terms cannot be demetaphorized. The picture of eating flesh and of drinking blood may be offensive in some cultures (the Jews themselves were forbidden to drink blood). However, meaning and symbol are so closely related here that one cannot demetaphorize without destroying the meaning of the passage.

You will not have life in yourselves (Jerusalem Bible “you will not have life in you”) is actually in the present tense (Revised Standard Version “you have no life in you”), but in the context it denotes a future possibility (New English Bible “you can have no life in you”). You will not have life in yourselves cannot be said in languages in which life cannot be possessed. Rather, it is necessary to speak of “living.” The most appropriate equivalent may be “you will not really live.” The explanation of this quality of life is contained in verse 54, which amplifies the meaning of verse 53 by introducing the theme of eternal life.

Quoted with permission from Newman, Barclay M. and Nida, Eugene A. A Handbook on the Gospel of John. (UBS Handbook Series). New York: UBS, 1980. For this and other handbooks for translators see here .