Charles Ellicott Commentary Titus 3:11

"knowing that such a one is perverted, and sinneth, being self-condemned." — Titus 3:11 (ASV)

Knowing that he that is such is subverted, and sinneth, being condemned of himself.—Better rendered, is perverted and sins, being self-condemned. Since you know, seeing that your reproofs and warnings have had no effect, that he is “thoroughly perverted”—the expression is a very strong one, and signifies literally has been turned inside out.

The same verb is used in the Septuagint translation of Deuteronomy 32:20, the “very froward generation” of the English version—having been warned once and again, he is without the excuse of ignorance, but sins on in the full consciousness of his willful and seditious life. His perverse conduct in stirring up factionalism in the Church publicly convicts him of doing the very wrong which in general he professes to condemn.

With these words the public or official portion of the Letter to the presiding presbyter in Crete closes. Paul had begun with directions how the church life of the island—up to this period apparently devoid of organization—was to be arranged; he concludes with instructions how to deal with any who presumed to set themselves in opposition to his plans for the government of the community. The central portion of the letter is occupied in discussing how Christian doctrine is to influence the lives of those accepting it, and especially it treats of the conduct of Christians towards the Pagan world, with whom they will necessarily be brought in contact.