Foreknowledge did not undo their weakness
Next after this, the Jew in Celsus says another silly thing: “How, if he foretold both the one who would betray him and the one who would deny him, would they not have feared him as a god, so that the one would no longer betray him and the other would not deny him?” (compare Matthew 26:21–25, 34). But the most wise Celsus did not see the contradiction in this passage. If Jesus foreknew as God, and his foreknowledge could not prove false, then it was not possible either for the man known as the future betrayer not to betray, or for the man shown to be the future denier not to deny. But if it was possible for the one not to betray and the other not to deny, so that not betraying and not denying would have come about in those who had learned of these things beforehand, then the one who said, “This man will betray and that man will deny,” was no longer speaking the truth.
For if he foreknew the man who would betray him, he saw the wickedness from which the betrayal would come, and this wickedness was in no way overturned by the foreknowledge. And again, if he had grasped who would deny him, he foretold that this man would deny him because he saw the weakness from which the denial would come; and that weakness was not going to be overturned so suddenly by the foreknowledge.
And where does he get this: “But they themselves betrayed and denied him without caring for him at all”? For it has been shown concerning the betrayer that it is false that he betrayed his teacher without having had any regard for him at all. And this is shown no less concerning the one who denied him, who after the denial “went out and wept bitterly” (Matthew 26:75; Luke 22:62).
Greek
Ἑξῆς δὲ τούτῳ καὶ ἄλλο εὔηθές φησιν ὁ παρὰ τῷ Κέλσῳ Ἰουδαῖος, ὅτι πῶς, εἴπερ προεῖπε καὶ τὸν προδώσοντα καὶ τὸν ἀρνησόμενον, οὐκ ἂν ὡς θεὸν ἐφοβήθησαν, ὡς τὸν μὲν μὴ προδοῦναι ἔτι τὸν δὲ μὴ ἀρνήσασθαι; καὶ οὐκ εἶδέ γε ὁ σοφώτατος Κέλσος ἐν τῷ τόπῳ τὴν μάχην, ὅτι εἰ μὲν ὡς θεὸς προέγνω καὶ οὐχ οἷόν τε ἦν αὐτοῦ τὴν πρόγνωσιν ψεύσασθαι, οὐχ οἷόν τε ἦν οὔτε τὸν ἐγνωσμένον ὡς προδώσοντα μὴ προδοῦναι οὔτε τὸν ἐλεγχθέντα ἀρνησόμενον μὴ ἀρνήσασθαι· εἰ δ᾿ οἷόν τ᾿ ἦν τόνδε μὲν μὴ προδώσειν τόνδε δὲ μὴ ἀρνήσασθαι, ὡς καὶ γενέσθαι ἂν τὸ μὴ προδοῦναι καὶ τὸ μὴ ἀρνήσασθαι ἐν τοῖς ταῦτα προμεμαθηκόσιν, οὐκέτι ἀληθὴς ἦν ὁ λέγων ὅτι ὅδε μὲν προδώσει ὅδε δὲ ἀρνήσεται. καὶ γὰρ εἰ προέγνω προδώσοντα, τὴν πονηρίαν εἶδεν, ἀφ᾿ ἧς προδώσει, ἥτις οὐ πάντως ἐκ τῆς προγνώσεως ἀνετέτραπτο. πάλιν τε αὖ εἰ κατείληφε τὸν ἀρνησόμενον τὴν ἀσθένειαν ἰδὼν, ἀφ᾿ ἧς ἀρνήσεται, προεῖπεν ὅτι ἀρνήσεται· ἡ δ᾿ ἀσθένεια οὐκ ἔμελλεν ἀνατρέπεσθαι οὕτως ἀθρόως ἀπὸ τῆς προγνώσεως. πόθεν δὲ καὶ τό· ἀλλ᾿ αὐτοὶ προέδωκάν τε καὶ ἠρνήσαντο μηδὲν αὐτοῦ φροντίσαντες; ἐδείχθη γὰρ περὶ μὲν τοῦ προδόντος ὅτι ψεῦδος τὸ μηδαμῶς αὐτὸν πεφροντικότα τοῦ διδασκάλου προδεδωκέναι· οὐδὲν δ᾿ ἧττον καὶ περὶ τοῦ ἀρνησαμένου τοῦτο δείκνυται, ὃς „ἐξελθὼν ἔξω“ μετὰ τὸ ἀρνήσασθαι „ἔκλαυσε πικρῶς.“