|On the Gospel of Judas|
For a thorough look at the "hard data" about this Judas document, I recommend Roger Pearse's treatment here.
The Gospel of Judas (GoJ), as of this writing, is the latest and greatest non-gospel Gospel to have captured the media's attention. The question of the hour is...why?
The experts all agree - even those routinely associated with positions unfriendly to evangelical Christianity - that GoJ was authored sometime in the second century, and was not written by Judas, nor by anyone who knew him. The manuscript itself - so well-invested in by National Geographic -- is a 3rd or 4th century Coptic translation. The Church author Irenaeus (c. 180 AD) mentions a heretical gospel with Judas as the star, and this is probably it as it matches what he describes. By the criteria for authorship laid out in Chapter 14, GoJ fails spectacularly on external tests of authenticity.
In terms of internal evidence of content, GoJ likewise fails spectacularly. GoJ is definitively the product of persons with a "Gnostic" orientation - members of a group that held that a special gnosis, or knowledge, was required for salvation. This too is widely recognized. What sort of knowledge, we might ask? A passage from the text gives us a good idea:
Jesus said to them, "How do you know me? Truly [I] say to you, no generation of the people that are among you will know me."
But their spirits did not dare to stand before [him], except for Judas Iscariot. He was able to stand before him, but he could not look him in the eyes, and he turned his face away. Judas [said] to him, "I know who you are and where you have come from. You are from the immortal realm of Barbelo. And I am not worthy to utter the name of the one who has sent you." Knowing that Judas was reflecting upon something that was exalted, 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. For someone else will replace you, in order that the twelve [disciples] may again come to completion with their god." Judas said, "Master, as you have listened to all of them, now also listen to me. For I have seen a great vision." When Jesus heard this, he laughed and said to him, "You thirteenth spirit, why do you try so hard? But speak up, and I shall bear with you."
"The twelve aeons of the twelve luminaries constitute their father, with six heavens for each aeon, so that there are seventy-two heavens for the seventy-two luminaries, and for each  [of them five] firmaments, [for a total of] three hundred sixty [firmaments …]. They were given authority and a [great] host of angels [without number], for glory and adoration, [and after that also] virgin spirits, for glory and [adoration] of all the aeons and the heavens and their firmaments.
The Jesus of GoJ, with his airy pontificating over aeons and luminaries, is teaching the sort of thing that would never come from the mouth of a hardtack peasant teacher in first century Jewish Palestine. This Jesus is an elitist who mocks the disciples for not being as informed as he is about things that they never would have cared about, historically speaking. If the historical Jesus had pulled this sort of thing on a Peter, chances are he and the other disciples would have beat Jesus up, not held him in high regard. At the very least this sort of Jesus would have been a rogue and a deviant who would have been totally ignored by his Jewish contemporaries, or regarded as a madman. This is the sort of thing Gnostics cared about, having the leisure, as they did, to contemplate such things, which a peasant farmer, artisan, or fisherman did not. And this, too, is widely recognized by scholars of all persuasions: That GoJ contains little, if anything, that could be traced back to a historical Jesus or Judas (that was not already reflected in the canonical texts).
So the question of the hour, again: If all of this is true, why was there even hype about GoJ?
Some of it came of non-experts who made incorrect statements about the provenance of GoJ. Herbert Krosney, for example, said on behalf of National Geographic, that GoJ "was as close to a contemporary account of what happened as many other accounts of Jesus." Other media outlets hyped GoJ with the analysis that it could cause a "crisis of faith" and "challenge our deepest beliefs."
But by far, the greater of the guilty parties in the celebration of hype are those who have used GoJ to promulgate the idea of "diversity" in early Christianity. The underlying theme here is that GoJ presents another "point of view" that deserves a hearing. It is merely assumed that by existing at all, it warrants attention. It is also assumed that the Jesus of GoJ is a much better one than sold in the canonical Gospels. Krosney in particular was moved by the fact that Jesus in GoJ laughed (whereas the canonical Jesus did not). Apparently, a warmer, fuzzier Jesus is all the more reason to grant a document credence.
Now this is not to say that it does not warrant attention of some sort. The simple fact is that either one or the other view about Jesus (the canonical Gospels, or GoJ) is right while the other is wrong, or else both are wrong. The Jesus of the canonical Gospels nestles comfortably in his setting: that of rural Palestine of the first century. The Jesus of GoJ is one that comes from the urban leisure class, at best. Which view is more likely to be wrong? That's not hard to decide. While GoJ should certainly have interest for those tracing deviant views of Jesus at a later date, to regard it as something from which an authentic memory of the Jesus of the first century can be gleaned is to suggest something that requires a tremendous burden of proof to fulfill.
But that is precisely what is not done. Authors like Krosney are giving GoJ credence that they would never give the canonical Gospels. It is odd indeed to see how this works: Here we have in GoJ a single copy, written 300 or more years after the period it is alleged to be describing, and with no external attestation earlier than Irenaeus some 150 years after the time of Jesus. On the other hand, we have the canonical Gospels, with much more and greater textual and external attestation, and they are treated as second class. One wonders what would happen if, say, Luke had been unknown until now, and then a single copy from the 4th century were discovered. Would Krosney and his ideological partners suggest that this new document contained authentic memories?
Thus the goal is, as one such promoter put it, to "explode the myth of a monolithic Christianity." But aside from scholars who study deviant movements - in terms of the everyday Christian - what concern ought there to be for diversity of error?
In the end, there can only be one story of history that is correct; the rest must be wrong, or all stories are wrong. GoJ and the canonical Gospels offer mutually exclusive portraits of Jesus. Our message to those who surround documents like GoJ with pomp and circumstance is: Diversity of views is irrelevant to what actually happened.
 A survey of views:
Bart D. Ehrman, The Lost Gospel of Judas Iscariot (Oxford University Press, 2006), 8, 102, says that the manuscript gets a carbon dating to 280 A.D., and believes that most scholars will opt for a date 140-150 A.D., with a possible wider range of 90-180. Ehrman says that GoJ presupposes Acts, and is not earlier than the canonical gospels
Stanley Porter and Gordon L. Heath, The Lost Gospel of Judas (Eerdmans, 2007), 41, 79, 95, date the manuscript between 300-350 A.D. and note the external testimony of two writers (including Irenaeus) of its inauthenticity with respect to Judas. They detect 13 episodes in it that are derived from the canonical Gospels.
James Robinson, The Secrets of Judas (Harper: 2006), 59, dates it between 130-170 A.D.
Elaine Pagels and Karen King, Reading Judas (Viking 2007), xii, date it to the middle of 2nd century.
 Ehrman, ibid., vii: "It is in fact a Gnostic Gospel." Porter and Heath, ibid., 28-30, identify certain Gnostic beliefs in the text, such as the need for a special gnosis for salvation; matter/spirit dualism in which matter is regarded as evil, and the creation of the material world by a lesser god.
 Ehrman, ibid. 172: "It is not a historically accurate report about the man Judas himself."
 Herbert Krosney, The Lost Gospel (National Geographic, 2006), 48.
 Porter and Heath, ibid., 2.
 Krosney, ibid., 278. The irony in this is that, as pointed out by N.T. Wright, Judas and the Gospel of Jesus (Baker, 2006), 54, Jesus in GoJ is laughing in mockery at those who believe false things - and is thus far from the comforting figure that Krosney imagines.