As to the words of St. Peter to Simon Magus, from which the Novatians infer that there was no forgiveness for the latter, it is pointed out that St. Peter, knowing his evil heart, might well use words of doubt, and then by some Old Testament instances it is pointed out that “perchance” does not exclude forgiveness. The apostles transmitted to us that penitence, the fruits of which are shown in the case of David. St. Ambrose then adduces the example of the Ephraimites, whose penitence must be followed in order to gain the divine mercy and the sacraments.
29. The Novatians bring up a question from the words of the Apostle Peter. Because he said, “if perchance,” they think that he did not imply that forgiveness would be granted on repentance. But let them consider concerning whom the words were spoken: of Simon, who did not believe through faith, but was meditating trickery. So too the Lord to him who said, “Lord, I will follow You withersoever You go,” replied, “Foxes have holes.” For He knew that the man's sincerity was not wholly perfect. If, then, the Lord refused to him who was not baptized permission to follow Him, because He saw that he was not sincere, do you wonder that the Apostle did not absolve him who after baptism was guilty of deceit, and whom he declared to be still in the bond of iniquity?
30. But let this be my answer to them. As to myself, I say that Peter did not doubt, and I do not think that so great a question can be burked by the questionable interpretation of a single word. For if they think that Peter doubted, did God doubt, Who said to the prophet Jeremiah: “Stand in the court of the Lord's house, and you shall give an answer to all Judah, to those who come to worship in the Lord's house, even all the words which I have appointed for you to answer them. Keep not back a word, perchance they will hearken and be converted.” Let them say, then, that God also knew not what would happen.
31. But ignorance is not implied in that word, but the common custom of holy Scripture is observed, in order to simplicity of utterance. Inasmuch as the Lord says also to Ezekiel: “Son of man, I will send you unto the house of Israel, to those who have angered Me, both themselves and their fathers, unto this day, and you shall say unto them, Thus says the Lord, if perchance they will hear and be afraid.” Did He not know that they could or could not be converted? So, then, that expression is not always a proof of doubt.
32. Lastly, the wise men of this world, who stake all their reputation on expressions and words, do not everywhere use the Latin word forte, “perchance,” or its Greek equivalent τάχα, as an expression of doubt. And so they say that their earliest poet used the words,...ἦ ῾ τάχα χήρη
...ἔσομαι,
which is, “I shall soon be a widow;” and the passage goes on:... τάχα γάρ σε κατακνέουσιν ᾿Αχαιοὶ
πάντες εφορμηθέντες.
But he had no doubt that when all were Joining in the attack one might well be laid low by all.
33. But let us use our own instances rather than foreign ones. You find in the Gospel that the Son Himself says of the Father (when He had sent His servants to His vineyard, and they had been slain), that the Father said, “I will send My well-beloved Son, perchance they will reverence Him.” And in another place the Son says of Himself: “You know neither Me nor My Father; for if you knew Me, you would perchance know My Father also.”
34. If, then, Peter used those words which were used by God without any prejudice to His knowledge, why should we not assume that Peter also used them without prejudice to his belief? For he could not doubt concerning the gift of Christ, Who had given him the power of forgiving sins; especially since he was bound not to leave any place for the craftiness of heretics who desire to deprive men of hope, in order the more easily to insinuate into the despairing their opinion as to the reiteration of baptism.
35. But the apostles, having this baptism according to the direction of Christ, taught repentance, promised forgiveness, and remitted guilt, as David taught when he said: “Blessed are they whose transgressions are forgiven, and whose sins are covered. Blessed is the man to whom the Lord has not imputed sin.” He calls each blessed, both him whose sins are remitted by the font, and him whose sin is covered by good works. For he who repents ought not only to wash away his sin by his tears, but also to cover and hide his former transgressions by amended deeds, that sin may not be imputed to him.
36. Let us, then, cover our falls by our subsequent acts; let us purify ourselves by tears, that the Lord our God may hear us when we lament, as He heard Ephraim when weeping, as it is written: “I have surely heard Ephraim weeping.” And He expressly repeats the very words of Ephraim: “You have chastised me and I was chastised, like a calf I was not trained.” For a calf disports itself, and leaves its stall, and so Ephraim was untrained like a calf far away from the stall; because he had forsaken the stall of the Lord, followed Jeroboam, and worshipped the calves, which future event was prophetically indicated through Aaron, namely, that the people of the Jews would fall after this manner. And so repenting, Ephraim says: “Turn me, and I shall be turned, for You are the Lord my God. Surely in the end of my captivity I repented, and after I learned I mourned over the days of confusion, and subjected myself to You because I received reproach and made You known.”
37. We see how to repent, with what words and with what acts, that the days of sin are called “days of confusion;” for there is confusion when Christ is denied.
38. Let us, then, submit ourselves to God, and not be subject to sin, and when we ponder the remembrance of our offenses, let us blush as though at some disgrace, and not speak of them as a glory to us, as some boast of overcoming modesty, or putting down the feeling of justice. Let our conversion be such, that we who did not know God may now ourselves declare Him to others, that the Lord, moved by such a conversion on our part, may answer to us: “Ephraim is from youth a dear son, a pleasant child, for since My words are concerning him, I will verily remember him, therefore have I hastened to be over him; I will surely have mercy on him, says the Lord.”
39. And what mercy He promises us, the Lord also shows, when He says further on: “I have satiated every thirsty soul, and have satisfied every hungry soul. Therefore, I awaked and beheld, and My sleep was sweet unto Me.” We observe that the Lord promises His sacraments to those who sin. Let us, then, all be converted to the Lord.
Source: On Repentance (New Advent)