The Gospel of Judas is a fragmentary, poorly written second century Gnostic document, written by an unknown author, which contradicts earlier and more credible sources. It doesn't give us any significant new information about Jesus, Judas, or first century Christianity. It's more relevant to second century Gnosticism than it is to people and events of the first century Christian mainstream.
Though the document doesn't have the sort of significance that its media coverage suggests, it does serve as a useful backdrop for the canonical gospels in another sense. One of my initial impressions after reading the Gospel of Judas was gratitude for the Biblical gospels. In dating, credibility, composition, and other respects, the canonical gospels are of far higher quality than the Gospel of Judas.
Critics often make much of the differences between the gospel of John and the Synoptics, but those differences aren't contradictions, and they're minor in comparison to the differences between the four Biblical gospels and the Gospel of Judas. If you want some idea of how different the canonical gospels would have been from each other if the authors didn't have much concern for historicity, then read the Gospel of Judas and compare it to the canonical gospels. The Jesus of the Gospel of Judas has some general similarities with the Jesus of the New Testament, such as a tendency to address spiritual matters and to correct his disciples. But the behavior and teachings of the Jesus of the Gospel of Judas are also radically different from those of the New Testament Jesus.
The Jesus of the Gospel of Judas is frequently laughing, which is a characteristic that the New Testament authors know nothing about. If Jesus laughed that often, you would have to wonder why that characteristic isn't reflected in any of the canonical gospels, which are relatively lengthy documents that address many aspects of Jesus' life. And the fabricated Jesus of the Gospel of Judas, unlike the New Testament Jesus, doesn't show much love for his disciples, aside from Judas.
The Gnostic teachings of the Jesus of the Gospel of Judas are also radically different from the teachings of the canonical Jesus. Again, if the New Testament authors were as unconcerned about or as careless about historicity as many modern critics suggest, then why don't we see the sort of wide divergence among the canonical gospels that we see between those gospels and the Gospel of Judas? Reading the Gospel of Judas ought to remind us of how unified, how historically credible the canonical gospels are in contrast.
Years ago, when I was reading some portions of Philip Schaff's church history, I put together some of Schaff's comments on the significance of the Bible. I want to close with that quote, which some of you may have seen me post before in other forums. The contrast between the canonical gospels and the Gospel of Judas reminds me of what Schaff wrote:
"Although these [New Testament] books were called forth apparently by special and accidental occasions, and were primarily addressed to particular circles of readers and adapted to particular circumstances, yet, as they present the eternal and unchangeable truth in living forms, they suit all circumstances and conditions. Tracts for the times, they are tracts for all times; intended for Jews and Greeks of the first century, they have the same interest for Englishmen and Americans of the nineteenth century. They are to this day not only the sole reliable and pure fountain of primitive Christianity, but also the infallible rule of Christian faith and practice. From this fountain the church has drunk the water of life for more than fifty generations, and will drink it till the end of time....Theological systems come and go, and draw from that treasury [of scripture] their larger or smaller additions to the stock of our knowledge of the truth; but they can never equal that infallible word of God, which abideth forever. 'Our little systems have their day, they have their day and cease to be: they are but broken lights of Thee, and Thou, O God, art more than they.' The New Testament evinces its universal design in its very style, which alone distinguishes it from all the literary productions of earlier and later times. It has a Greek body, a Hebrew soul, and a Christian spirit which rules both. The language is the Hellenistic idiom; that is, the Macedonian Greek as spoken by the Jews of the dispersion in the time of Christ; uniting, in a regenerated Christian form, the two great antagonistic nationalities and religions of the ancient world. The most beautiful language of heathendom and the venerable language of the Hebrews are here combined, and baptized with the spirit of Christianity, and made the picture of silver for the golden apple of the eternal truth of the gospel. The style of the Bible in general is singularly adapted to men of every class and grade of culture, affording the child the simple nourishment for its religious wants, and the profoundest thinker inexhaustible matter of study. The Bible is not simply a popular book, but a book of all nations, and for all societies, classes, and conditions of men. It is more than a book, it is an institution which rules the Christian world....We now descend from the primitive apostolic church to the Graeco-Roman; from the scene of creation to the work of preservation; from the fountain of divine revelation to the stream of human development; from the inspirations of the apostles and prophets to the productions of enlightened but fallible teachers. The hand of God has drawn a bold line of demarcation between the century of miracles and the succeeding ages, to show, by the abrupt transition and the striking contrast, the difference between the work of God and the work of man, and to impress us the more deeply with the supernatural origin of Christianity and the incomparable value of the New Testament....Not one [of the church fathers] compares for a moment in depth and spiritual fulness with a St. Paul or St. John; and the whole patristic literature, with all its incalculable value, must ever remain very far below the New Testament. The single epistle to the Romans or the Gospel of John is worth more than all commentaries, doctrinal, polemic, and ascetic treatises of the Greek and Latin fathers, schoolmen, and reformers....If we compare these [post-apostolic] documents with the canonical Scriptures of the New Testament, it is evident at once that they fall far below in original force, depth, and fulness of spirit, and afford in this a strong indirect proof of the inspiration of the apostles....For by the wise ordering of the Ruler of history, there is an impassable gulf between the inspiration of the apostles and the illumination of the succeeding age, between the standard authority of holy Scripture and the derived validity of the teaching of the church. 'The Bible' - to adopt an illustration of a distinguished writer - 'is not like a city of modern Europe, which subsides through suburban gardens and groves and mansions into the open country around, but like an Eastern city in the desert, from which the traveler passes by a single step into a barren waste.' The very poverty of these post-apostolic writings renders homage to the inexhaustible richness of the apostolic books which, like the person of Christ, are divine as well as human in their origin, character, and effect....The Bible is a book of holy men, but just as much a book of God, who made those men witnesses of truth and sure teachers of the way of salvation." (The Master Christian Library [Albany, Oregon: AGES Software, 1998], History of the Christian Church, Vol. 1, pp. 457-458; Vol. 2, pp. 22, 495-496, 500-501; Vol. 7, p. 26)