2 Timothy 2:17

Ver. 17. And their word will eat as a gangrene. A gangrene is described by Galen as “an eating sore,” or a tumour in the state between inflammation and entire mortification, and tending to the latter. Though not strictly synonymous with our word cancer, it might not improperly be represented in popular language as a sort of cancerous affection, and, like this, spreading or finding pasture (νομὴν ἕξει) on the contiguous parts of the body. It was therefore a fitting image of the evil tendency in such false teaching to diffuse itself among the people, because ministering in one respect or another to the weaknesses and follies of human nature. As the moral disease in the teachers themselves would get worse, so their word would eat outwards, catching hold of others, and bringing them under its noxious influence. It is a general statement, but to what extent applicable then, or to any particular error arising in later times, must always depend, partly on the kind of error which seeks propagation, and partly in the more or less congenial elements amid which it has to work.