The first part of this verse concludes the sentence that began in verse 16. Revised Standard Version retains the Greek form here, but Good News Translation starts a new sentence.

As already mentioned, their can refer either to “godless chatter” in the previous verse (so Good News Translation “Such teaching”) or to people. Talk is literally “word” but here refers to the content of “godless chatter,” hence Good News Translation “teaching,” and not to the way it is done.

Will eat its way translates a metaphorical Greek expression (literally “will have pasture”). Gangrene occurs only here in the New Testament and can also refer to cancer or ulcers. But more likely it refers here to an open sore that spreads and eats away at the healthy parts of the body. It is therefore an appropriate figure for wrong and unhealthy doctrines that spread among Christians and change their lives for the worse.

Two men are mentioned as examples of those who have been spreading this kind of gangrene in the church. Hymenaeus occurs only here and in 1 Tim 1.20; most likely the same person is meant. Other than the mention of his name, we know nothing about him. His name is derived from “Hymen,” who is the Greek god of weddings. Philetus is mentioned only here in the whole New Testament. The meaning of his name in Greek is “amiable.” It is not, however, recommended that the meanings of these names be translated. The usual practice is to transliterate names as names, unless the meaning of the name is significant for the passage.

Quoted with permission from Arichea, Daniel C. and Hatton, Howard A. A Handbook on Paul’s Second Letter to Timothy. (UBS Handbook Series). New York: UBS, 1995. For this and other handbooks for translators see here .