When he left the bishop’s dwelling Jean Valjean, as we know, had been in a state of mind unlike anything he had ever experienced before and was quite unable to account for what was taking place within him. He had sought to harden his heart against the old man’s saintly act and moving words. “You have promised me to become an honest man. I am buying your soul. I am rescuing it from the spirit of perversity and giving it to God.” The words constantly returned to him and he sought to suppress them with arrogance, which in all of us is the stronghold of evil. Obscurely he perceived that the priest’s forgiveness was the most formidable assault he had ever sustained; that if he resisted it his heart would be hardened once and for all, and that if he yielded he must renounce the hatred which the acts of men had implanted in him during so many years, and to which he clung. He saw dimly that this time he must either conquer or be conquered, and that the battle was now joined, a momentous and decisive battle between the evil in himself and the goodness in that other man.

[Quand Jean Valjean était sorti de chez l’évêque, on l’a vu, il était hors de tout ce qui avait été sa pensée jusque-là. Il ne pouvait se rendre compte de ce qui se passait en lui. Il se roidissait contre l’action angélique et contre les douces paroles du vieillard. « Vous m’avez promis de devenir honnête homme. Je vous achète votre âme. Je la retire à l’esprit de perversité et je la donne au bon Dieu. » Cela lui revenait sans cesse. Il opposait à cette indulgence céleste l’orgueil, qui est en nous comme la forteresse du mal. Il sentait indistinctement que le pardon de ce prêtre était le plus grand assaut et la plus formidable attaque dont il eût encore été ébranlé ; que son endurcissement serait définitif s’il résistait à cette clémence ; que, s’il cédait, il faudrait renoncer à cette haine dont les actions des autres hommes avaient rempli son âme pendant tant d’années, et qui lui plaisait ; que cette fois il fallait vaincre ou être vaincu, et que la lutte, une lutte colossale et définitive, était engagée entre sa méchanceté à lui et la bonté de cet homme.]

Victor Hugo (1802-1885) French writer
Les Misérables, Part 1 “Fantine,” Book 2 “The Fall,” ch. 13 (1.2.13) (1862) [tr. Denny (1976)]
    (Source)

(Source (French)). Alternate translations:

When Jean Valjean left the bishop's house, as we have seen, his mood was one that he had never known before. He could understand nothing of what was passing within him. He set himself stubbornly in opposition to the angelic deeds and the gentle words of the old man, “you have promised me to become an honest man. I am purchasing your soul, I withdraw it from the spirit of perversity, and I give it to God Almighty." This came back to him incessantly. To this celestial tenderness, he opposed pride, which is the fortress of evil in man. He felt dimly that the pardon of this priest was the hardest assault, and the most formidable attack which he had yet sustained ; that his hardness of heart would be complete, if it resisted this kindness; that if he yielded, be must renounce that hatred with which the acts of other men had for so many years filled his soul, and in which he found satisfaction; that, this time, he must conquer or be conquered, and that the struggle, a gigantic and decisive struggle, had begun between his own wickedness, and the goodness of this man.
[tr. Wilbour (1862)]

When Jean Valjean quitted the bishop’s house, he was lifted out of his former thoughts, and could not account for what was going on within him. He stiffened himself against the angelic deeds and gentle words of the old man: “You have promised me to become an honest man. I purchase your soul; I withdraw it from the spirit of perverseness, and give it to God.” This incessantly recurred to him, and he opposed to this celestial indulgence that pride which is within us as the fortress of evil. He felt instinctively that this priest’s forgiveness was the greatest and most formidable assault by which he had yet been shaken; that his hardening would be permanent if he resisted this clemency; that if he yielded he must renounce that hatred with which the actions of other men had filled his soul during so many years, and which pleased him; that this time he must either conquer or be vanquished, and that the struggle, a colossal and final struggle, had begun between his wickedness and that man’s goodness.
[tr. Wraxall (1862)]

When Jean Valjean left the Bishop's house, he was, as we have seen, quite thrown out of everything that had been his thought hitherto. He could not yield to the evidence of what was going on within him. He hardened himself against the angelic action and the gentle words of the old man. "You have promised me to become an honest man. I buy your soul. I take it away from the spirit of perversity; I give it to the good God."
This recurred to his mind unceasingly. To this celestial kindness he opposed pride, which is the fortress of evil within us. He was indistinctly conscious that the pardon of this priest was the greatest assault and the most formidable attack which had moved him yet; that his obduracy was finally settled if he resisted this clemency; that if he yielded, he should be obliged to renounce that hatred with which the actions of other men had filled his soul through so many years, and which pleased him; that this time it was necessary to conquer or to be conquered; and that a struggle, a colossal and final struggle, had been begun between his viciousness and the goodness of that man.
[tr. Hapgood (1887)]

When Jean Valjean left the bishop's house, as we saw, his thoughts were unlike any he had ever known before. He could understand nothing of what was going on inside him. He stubbornly resisted the angelic deeds and the gentle words of the old man, "You have promised me to become an honest man. I am purchasing your soul. I withdraw it from the spirit of perdition, and I give it to God!" This kept coming back to him. In opposition to this celestial tenderness, he summoned up pride, the fortress of evil in man. He dimly felt that this priest's pardon was the hardest assault, the most formidable attack he had ever sustained; that his hardness of heart would be complete, if it resisted this kindness; that if he yielded, he would have to renounce the hatred with which the acts of other men had for so many years filled his soul, and in which he found satisfaction; that, this time, he must conquer or be conquered, and that the struggle, a gigantic and decisive struggle, had begun between his own wrongs and the goodness of this man.
[tr. Wilbour/Fahnestock/MacAfee (1987)]

When jean Valjean left the bishop's house he was, as we have seen, in what was to him an entirely different mental universe. He could not undersdtand what was going on inside him. He hardened himself against the old man's angelic deed and gentle words. "You promised to become an honest man. I'm buying your soul. I'm redeeming it from the spirit of iniquity and giving it to the good Lord." This kept coming back to him. This heavenly kindness he countered with pride -- the fortress of evil, as it were, within us. He had the indistinct feeling that this priest's forgiveness was the greatest assault and most tremendous attack he had ever experience. That if he resisted this clemency the hardening of his heart would be definitive. That if he yielded he would be obliged to renounce that hatred with which the deeds of other men had filled his soul over so many years, a hatred he relished. That this time he had to vanquish or be vanquished, and that the battle had been joined, a colossal and decisive battle, between his own wickedness and that man's goodness.
[tr. Donougher (2013)]