Here is Elaine Pagels writing on that.
The Gospel Truth
By ELAINE PAGELS
Published: April 8, 2006
The secret account of the revelation that Jesus spoke in conversation with Judas Iscariot during a week three days before he celebrated Passover. ... Jesus said to him, "Step away from the others and I shall tell you the mysteries of the kingdom. It is possible for you to reach it, but you will grieve a great deal."
— The Gospel of Judas
THE Gospel of Judas, which remained virtually unknown to us from the time it was written 1,700 years ago until its publication this week, says that when Judas Iscariot handed Jesus over to the Romans, he was acting on orders from Jesus to carry out a sacred mystery for the sake of human salvation: "Jesus said to Judas, 'Look, you have been told everything. You will exceed all of them. For you will sacrifice the man that clothes me.' "
For nearly 2,000 years, most people assumed that the only sources of tradition about Jesus and his disciples were the four gospels in the New Testament. But the unexpected discovery at Nag Hammadi in 1945 of more than 50 ancient Christian texts proved what church fathers said long ago: that Matthew, Mark, Luke and John are only a small selection of gospels from among the dozens that circulated among early Christian groups. But now the Gospel of Judas — like the Gospel of Thomas, the Gospel of Mary Magdalene and many others — opens up new perspectives on familiar gospel stories.
Many scholars who first read these gospels had been taught that they were "heretical," which meant they were the wrong gospels. When I was introduced to them as a student, we called them "Gnostic" gospels, the name given to them nearly 2,000 years ago by Irenaeus, one of the fathers of the church, who denounced them as false and "heretical."
Yet those early Christians who loved and revered such texts did not think of themselves as heretics, but as Christians who had received not only what Jesus preached publicly, but also what he taught his disciples when they were talking privately. Many regarded these secret gospels not as radical alternatives to the New Testament Gospels, but as advanced-level teaching for those who had already received Jesus' basic message. Even the Gospel of Mark tells us that Jesus explained things to certain disciples in private, entrusting to them alone "the mystery of the Kingdom of God."
If so, Jesus would have been doing what many other rabbis did then, and most teachers do today. Many of the gospels not included in the New Testament claim to offer secret teaching: Thus the Gospel of Thomas opens, "These are the secret words which the living Jesus spoke, and Didymus Judas Thomas wrote them down." The Gospel of Mary Magdalene reveals what Jesus showed Mary in a vision, and the Gospel of Judas claims to offer a spiritual mystery entrusted to Judas alone.
Irenaeus, however, insisted that Jesus did not teach any of his disciples secretly; such secret revelations, he said, were all illegitimate, and those who revered them heretics. Knowing many such gospels circulated among early Christian groups, Irenaeus wrote that "the heretics say that they have more gospels than there actually are; but really, they have no gospel that is not full of blasphemy."
Many of these secret writings, however, were still read and revered by Christians 200 years later when Bishop Athanasius of Alexandria, an admirer of Irenaeus, wrote an Easter letter to Christians in Egypt. He ordered them to reject what he called those "secret, illegitimate books" and keep only 27 approved ones. The 27 he named constitute the earliest known list of the New Testament canon, which Athanasius intended above all to be a guideline for books to be read publicly in church. The New Testament Gospels, which contain much that Jesus taught in public, were the most obvious books to put on that list. The secret books, which contained paradox and mystery akin to the mystical teachings of kabbalah, were not considered suitable for beginners.
What in the Gospel of Judas, published this week by the National Geographic Society (disclosure: I was a consultant on the project), goes back to Jesus' actual teaching, and how would we know? And what else was there in the early Christian movement that we had not known before? These are some of the difficult questions that the discoveries raise for us — issues that historians are already debating. What is clear is that the Gospel of Judas has joined the other spectacular discoveries that are exploding the myth of a monolithic Christianity and showing how diverse and fascinating the early Christian movement really was.
Startling as the Gospel of Judas sounds, it amplifies hints we have long read in the Gospels of Mark and John that Jesus knew and even instigated the events of his passion, seeing them as part of a divine plan. Those of us who go to church may find our Easter reflections more mysterious than ever.
Elaine Pagels, the author of "The Gnostic Gospels" and "Beyond Belief: The Secret Gospel of Thomas," is a professor of religion at Princeton.