Knowing that he that is such is subverted, and sinneth, being condemned of himself. Is subverted - Is turned out of the way in which he may be saved, and consequently sinneth - enters into that way that leads to destruction.
Being condemned of himself - This refers to the Judaizing teacher, who maintained his party and opinions for filthy lucre's sake. He was conscious of his own insincerity; and that he proclaimed not his system from a conscientious love of truth, but from a desire to get his livelihood. Were the Church in all countries, whether established by law or unestablished, strictly scrutinized, multitudes of heretics of this kind would be found. And perhaps this is the only bad sense in which the word should be understood.