The recently discovered Gospel of Judas has created much controversy among scholars. While it is clear that Judas is liable for Jesus' crucifixion in this text, it is much debated whether his actions should be understood positively or negatively. This article suggests that focusing on how the Gospel of Judas evaluates the salvific meaning of Jesus' crucifixion alongside the New Testament gospels and other early Christian writings may provide a key for solving this problem. In this way, the Gospel of Judas can be seen as a rare attempt to unravel what Irenaeus aptly termed ‘the mystery of the betrayal’.