They put away—"thrust from them"—faith and a good conscience; they wilfully abandoned the great central facts regarding Christ, and so they "made shipwreck concerning the faith.
The doctrine of these three heretical teachers, Hymenaeus, Alexander and Philetus, was one of the early forms of Gnosticism.
That thus in the case of everyone who was set free from the consequences of wrongdoing, "the resurrection was past already," and that the body did not participate in the blessedness of the future life, but that salvation consisted in the soul's complete deliverance from all contact with a material world and a material body.
So pernicious were these teachings of incipient Gnosticism in the Christian church that, according to Paul, they quickly spread "like gangrene."
The way in which Paul dealt with those who taught such deadly error was by resorting to the same extreme measures as he had employed in the case of the immoral person at Corinth: he delivered Hymenaeus and Alexander to Satan, that they might learn not to blaspheme.