ACC ~ Titus 1 v16

THE EVIL WILL. CHRYSOSTOM: But he that has a weak soul makes everything unclean, and if there be set abroad a scrupulous inquiry into what is clean or unclean, he will touch nothing. … Yet Paul says not so; he turns the whole matter upon themselves. For nothing is unclean, he says, but themselves, their mind and their conscience; and nothing is more unclean than these; but an evil will is unclean. HOMILIES ON TITUS 3.

JEROME: Some think that this verse applies only to those who deny the faith during a persecution, but the apostle contends that all perverse behavior denies God. COMMENTARY ON TITUS.

WHAT IS DENIED BY DEEDS CAN BE SAID BY DEEDS. AUGUSTINE: All the heresies … they all say, “Jesus is Lord.” And he’s not, of course, going to eliminate from the kingdom of heaven those whom he finds to be in the Holy Spirit; and yet he did say, “Not everyone who says to me, Lord, Lord, will enter into the kingdom of heaven.”But: “Nobody can say: Jesus is Lord, except in the Holy Spirit”; nobody at all, evidently; but in the sense in which it was meant, that is in deeds. … The same apostle, you see, also says of some people, “They claim to know the Lord but deny it by their deeds.” As it can be denied by deeds, so it can be said by deeds. SERMONS 269.4.

QUALITY IS REVEALED. LEO THE GREAT: Our peace also has its dangers, dearly beloved. In vain do people feel secure as a result of freedom for their faith if they do not resist the desires of vice. By the quality of works is the human heart made known, and outward actions disclose the beauty of souls. There are some, as the apostle says, who “profess to know God but deny him through their deeds.” Truly the guilt of denial is incurred when the ears have heard what is good but the conscience does not hold on to it. The frailty of the human condition easily slides into sin. SERMONS 37.4.