I write these things not wishing to cause distress to the heretics or to rejoice in their ill-treatment — God forbid; but, rather, rejoicing and being gladdened at their return. For what is more pleasing to the Faithful than to see the scattered children of God gathered again as one? Neither do I exhort you to place harshness above the love of men. May I not be so mad!
I beseech you to do and to carry out good to all men with care and assiduity, becoming all things to all men, as the need of each is shown to you; I want and pray you to be wholly harsh and implacable with the heretics only in regard to cooperating with them or in any way whatever supporting their deranged belief. For I reckon it hatred towards man and a departure from Divine love to lend support to error, so that those previously seized by it might be even more greatly corrupted.
As man I deliberately transgressed the divine commandment, when the devil, enticing me with the hope of divinity (cf. Gen. 3:5), dragged me down from my natural stability into the realm of sensual pleasure; and he was proud to have thus brought death into existence, for he delights in the corruption of human nature. Because of this, God became perfect man, taking on everything that belongs to human nature except sin (cf. Heb. 4:15); and indeed sin is not part of human nature, In this way, by enticing the insatiable serpent with the bait of the flesh. He provoked him to open his mouth and swallow it. This flesh proved poison to him, destroying him utterly by the power of the Divinity within it; but to human nature it proved a remedy restoring it to its original grace by that same power of the Divinity within it. For just as the devil poured out his venom of sin on the tree of knowledge and corrupted human nature once it had tasted it, so when he wished to devour the flesh of the Master he was himself destroyed by the power of the Divinity within it.
Almost every sin is committed for the sake of sensual pleasure; and sensual pleasure is overcome by hardship and distress arising either voluntarily from repentance, or else involuntarily as a result of some salutary and providential reversal. For if we would judge ourselves, we should not be judged; but when we are judged, we are chastened by the Lord, so that we should not be condemned with the world. (1 Cor. 11:31-32).