Adam Clarke on 2 Timothy 2:21

If a man therefore purge himself from these - He that takes heed to his ways and to his doctrines, and walks with God, will separate himself, not only from all false doctrine, but from all wicked men, and thus be sanctified and proper to be employed by the Master in every good word and work. The apostle has not made the application of these different similes, and it is very difficult to tell what he means.