In the next place, that He was betrayed by those whom He called His disciples, is a circumstance which the Jew of Celsus learned from the Gospels; calling the one Judas, however, “many disciples,” that he might seem to add force to the accusation. Nor did he trouble himself to take note of all that is related concerning Judas; how this Judas, having come to entertain opposite and conflicting opinions regarding his Master neither opposed Him with his whole soul, nor yet with his whole soul preserved the respect due by a pupil to his teacher.
For he that betrayed Him gave to the multitude that came to apprehend Jesus, a sign, saying, “Whomsoever I shall kiss, it is he; seize him,”— retaining still some element of respect for his Master: for unless he had done so, he would have betrayed Him, even publicly, without any pretence of affection. This circumstance, therefore, will satisfy all with regard to the purpose of Judas, that along with his covetous disposition, and his wicked design to betray his Master, he had still a feeling of a mixed character in his mind, produced in him by the words of Jesus, which had the appearance (so to speak) of some remnant of good.
For it is related that, “when Judas, who betrayed Him, knew that He was condemned, he repented, and brought back the thirty pieces of silver to the high priest and elders, saying, I have sinned, in that I have betrayed the innocent blood. But they said, What is that to us? You see to that;” — and that, having thrown the money down in the temple, he departed, and went and hanged himself. But if this covetous Judas, who also stole the money placed in the bag for the relief of the poor, repented, and brought back the thirty pieces of silver to the chief priests and elders, it is clear that the instructions of Jesus had been able to produce some feeling of repentance in his mind, and were not altogether despised and loathed by this traitor.
Nay, the declaration, “I have sinned, in that I have betrayed the innocent blood,” was a public acknowledgment of his crime. Observe, also, how exceedingly passionate was the sorrow for his sins that proceeded from that repentance, and which would not suffer him any longer to live; and how, after he had cast the money down in the temple, he withdrew, and went away and hanged himself: for he passed sentence upon himself, showing what a power the teaching of Jesus had over this sinner Judas, this thief and traitor, who could not always treat with contempt what he had learned from Jesus.
Will Celsus and his friends now say that those proofs which show that the apostasy of Judas was not a complete apostasy, even after his attempts against his Master, are inventions, and that this alone is true, viz., that one of His disciples betrayed Him; and will they add to the Scriptural account that he betrayed Him also with his whole heart? To act in this spirit of hostility with the same writings, both as to what we are to believe and what we are not to believe, is absurd. And if we must make a statement regarding Judas which may overwhelm our opponents with shame, we would say that, in the book of Psalms, the whole of the 108th contains a prophecy about Judas, the beginning of which is this: “O God, hold not Your peace before my praise; for the mouth of the sinner, and the mouth of the crafty man, are opened against me.” And it is predicted in this psalm, both that Judas separated himself from the number of the apostles on account of his sins, and that another was selected in his place; and this is shown by the words: “And his bishopric let another take.” But suppose now that He had been betrayed by some one of His disciples, who was possessed by a worse spirit than Judas, and who had completely poured out, as it were, all the words which he had heard from Jesus, what would this contribute to an accusation against Jesus or the Christian religion? And how will this demonstrate its doctrine to be false? We have replied in the preceding chapter to the statements which follow this, showing that Jesus was not taken prisoner when attempting to flee, but that He gave Himself up voluntarily for the sake of us all. Whence it follows, that even if He were bound, He was bound agreeably to His own will; thus teaching us the lesson that we should undertake similar things for the sake of religion in no spirit of unwillingness.
Source: Against Celsus (New Advent)