It is suggested in the Gospel, in no uncertain terms, that Judas is the only one of the disciples who truly understands Jesus. The heart of the Gospel of Judas communicates a revelation or a teaching that Jesus offered to Judas about the nature of the world and the nature of God in the world. It is this teaching about cosmology that is the content of the knowledge that Judas must understand in order to become enlightened. He does understand it; He becomes transfigured or enlightened and he does exactly what Jesus asks him to do. He turns him into the authorities.
Washington Post: Ancient 'Gospel of Judas' Translation Sheds New Light on Disciple
