The thoughts of this verse are similar to those in 5.24; 6.40,47; and 11.25. Obeys my teaching (see also New English Bible) is literally “keeps my word” (Jerusalem Bible). It may be translated in some languages “does what I teach him to do,” “behaves in accordance with what I have taught,” or even “does what I have told him.”

Will never die is literally “will never see death” (Jerusalem Bible). When these Jews take up Jesus’ words in the next verse, they change the metaphor somewhat by saying “will never taste death” (Revised Standard Version). “To see death” and “to taste death” are both idiomatic expressions meaning “to die”; “To see death” is a Hebraism, but the expression “to taste death” is not found in the Old Testament. However, it is found in other places in the New Testament (see Heb 2.9, for example). The death referred to in this verse is spiritual death, a fact which is misunderstood by Jesus’ opponents in the following dialogue.

In most languages one cannot preserve the literal idioms “to see death” and “to taste death.” “To see death” has sometimes been understood as “to see dead bodies.” Even worse, “to taste death” has been taken to mean “to eat a corpse” or “to partake of human flesh.” The translation will never die can lead to misinterpretation (especially if such a verse is completely isolated from its context). However, this bold figure of speech used by Jesus must be understood in terms of its wider context, which ultimately serves as a basis for understanding what he has said. Unless this expression is translated rather literally, it will be impossible for the reader to comprehend the reactions of Jesus’ opponents mentioned in the following verse.

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 .