1Tim 4:2

“Such are the words and deeds by which, in our own district of the Rhone, they have deluded many women, who have their consciences seared as with a hot iron. Some of them, indeed, make a public confession of their sins; but others of them are ashamed to do this, and in a tacit kind of way, despairing of [attaining to] the life of God, have, some of them, apostatized altogether; while others hesitate between the two courses, and incur that which is implied in the proverb, "neither without nor within;" possessing this as the fruit from the seed of the children of knowledge.”

“In what way then is she a virgin who has fallen away from the faith, who has devoted herself to the deceivers, who obeys the demons and honors falsehood? In what way is she a virgin who has a seared conscience? For the virgin must be pure not only in body but also in soul if she is going to receive the holy bridegroom.… Virginity is defined by holiness of body and soul. But if a woman is unholy and impure in each respect, how could she be a virgin?… But she shows me a pale face, wasted limbs, a shabby garment and gentle glance.… What is the good of all that when the eye of the soul is bold, for what could be more audacious than that eye encouraging her real eyes to consider the objects of God's creation as bad?”

“"Speaking lies in hypocrisy." This implies that they utter not these falsehoods through ignorance and unknowingly, but as acting a part, knowing the truth, but "having their conscience seared," that is, being men of evil lives. But why does he speak only of these heretics? Christ had before said, "Offenses must need come" (Matt. xviii. 7), and he had predicted the same in his parable of the sower, and of the springing up of the tares. But here admire with me the prophetic gift of Paul, who, before the times in which they were to appear, specifies the time itself. As if he had said, Do not wonder, if, at the commencement of the faith, some endeavor to bring in these pernicious doctrines; since, after it has been established for a length of time, many shall depart from the faith.”

“On the part of those deceived, the cause is also twofold: one is their falsity; the other is the perversity of their conscience. In regard to the first he says, of devils, i.e., of men possessed by a Devil; of devils I say, speaking lies: how long shall this be in the heart of the prophets that prophecy lies, and that prophesy the delusions of their own heart (Jer 23:36). And note that no one could deceive another with a simple lie, unless it was covered with the appearance of truth. And so, they never could succeed in deceiving unless they pretended to have a good intention, or put a cloak over their pretense or false authority: let no man deceive you with vain words (Eph 5:6); having an appearance indeed of godliness, but denying the power thereof. Now these avoid (2 Tim 3:5). And of devils, I say, having their conscience seared. Flesh is said to be seared, when it is corrupted by fire and is in such a condition that rot flows from it continuously. Thus, by means of the fire of a perverse will, of anger, of hatred, of concupiscence, the conscience is ulcerated and the false doctrine of devils continually issues from it: both their mind and their conscience are defiled (Titus 1:15).”