At the Last Supper, Jesus knew that it would be the last, and that he would be dead by the next day. Each of the Evangelists tells the story differently, but, according to John, Jesus spent the time he had left re-stating to the disciples the lessons he had taught them and trying to prop up their courage. At a certain point, however, he lost heart. “Very truly,” he said to his men, “one of you will betray me.” Who? they asked. And he answered, “It is the one to whom I give this piece of bread when I have dipped it in the dish.” He then dipped a piece of bread into a dish and handed it to Judas Iscariot, a disciple whom the Gospels barely mention before the scene of the Last Supper but who now becomes very important. Once Judas takes the bread, Satan “entered into” him, John says. Is that a metaphor, meaning that Jesus’ prediction enables Judas to betray him? Maybe so, maybe not, but Jesus soon urges him directly. “Do quickly what you are going to do,” he says. And so Judas gets up from the table and leaves. That night (or perhaps even before the Last Supper), he meets with the priests of the Temple, makes the arrangements for the arrest, and collects his reward, the famous thirty pieces of silver.

That is the beginning of Jesus’ end, and of Judas’s. Jesus is arrested within hours. Judas, stricken with remorse, returns to the priests and tries to give them back their money. They haughtily refuse it. Judas throws the coins on the floor. He then goes out and hangs himself. He dies before Jesus does.

Did Judas deserve this fate? If Jesus informs you that you will betray him, and tells you to hurry up and do it, are you really responsible for your act? Furthermore, if your act sets in motion the process—Christ’s Passion—whereby humankind is saved, shouldn’t somebody thank you? No, the Church says. If you betray your friend, you are a sinner, no matter how foreordained or collaterally beneficial your sin. And, if the friend should happen to be the Son of God, so much the worse for you.

For two thousand years, Judas has therefore been Christianity’s primary image of human evil. Now, however, there is an effort to rehabilitate him, the result, partly, of an archeological find. In 1978 or thereabouts, some peasants digging for treasure in a burial cave in Middle Egypt came upon an old codex—that is, not a scroll but what we would call a book, with pages—written in Coptic, the last form of ancient Egyptian. The book has been dated to the third or fourth century, but scholars believe that the four texts it contains are translations of writings, in Greek, from around the second century. When the codex was found, it was reportedly in good condition, but it then underwent a twenty-three-year journey through the notoriously venal antiquities market, where it suffered fantastic abuses, including a prolonged stay in a prospective buyer’s home freezer. (This caused the ink to run when the manuscript thawed.) The book was cracked in half, horizontally; pages were shuffled, torn out. By the time the codex reached the hands of restorers, in 2001, much of it was just a pile of crumbs. The repair job took five years, after which some of the book was still a pile of crumbs. Many passages couldn’t be read.

And then there was the strangeness of what could be read. In the twentieth century, Bible scholars repeatedly had to deal with ancient books—the Dead Sea scrolls, the Nag Hammadi library—that surfaced from the sands of the Middle East to wreak havoc with orthodoxy. These books said that much of what we call Christian doctrine predated Christ; that the universe was created by a female deity, and so on. The 1978 find—called the Codex Tchacos, for one of its successive owners, Frieda Tchacos Nussberger—was even more surprising, because one of its texts, twenty-six pages long, was entitled “The Gospel of Judas.” It wasn’t written by Judas. (We don’t know if there was a historical Judas Iscariot.) It was a story about Judas, and in it the great villain, the Christ-killer, was portrayed as Jesus’ favorite disciple, the only one who understood him.

The Codex Tchacos, like the Nag Hammadi library, was the work of an ancient religious party, mostly Christian, that we call Gnostic. In the second century, Christianity was not an institution but a collection of warring factions, each with its own gospels, each claiming direct descent from Jesus, each accusing the others of heresy, homosexuality, and the like. In the fourth century, one group, or group of groups, won out: the people now known as the proto-orthodox, because, once they won, their doctrines became orthodoxy. The proto-orthodox were centrist. They embraced both the Hebrew Bible and the new law proclaimed by Jesus; they said that Jesus was both God and man; they believed that the world was both full of blessings and full of sin. Of the many gospels circulating, they chose four, called Matthew, Mark, Luke, and John, which, by reason of their realism and emotional directness—their lilies of the field and prodigal sons—were most likely to appeal to regular people.

The Gnostics were different—visionary, exclusionary. They scorned the Hebrew Bible; they said that the world was utterly evil; they claimed that the key to salvation was not faith or good behavior but secret knowledge, which was their exclusive property. The Gospel of Judas is entirely in line with this view. In it, most people have no hope of getting to Heaven. As for Jesus, he was not a man but wholly divine, and therefore Judas didn’t really have him killed. (Only a mortal can be killed.) According to some commentators, this Jesus asked Judas to release him from the human form he had assumed in order to descend to earth. Judas did him a favor.

That supposed exoneration of Judas was the most exclaimed-over aspect of the Gospel of Judas. Far more shocking, however, was the book’s portrait of Jesus. We know Jesus from the New Testament as an earnest and charitable man. Here, by contrast, he is a joker, and not a nice one. Three times in this brief text, he bursts into laughter over his disciples’ foolishness. The first time, he comes upon them as they are celebrating the Eucharist. What’s so funny? they ask him—this is what we’re supposed to do. Maybe according to your god, Jesus says. But you represent our God, they say. You’re his son. Jesus now turns on them. What makes you think you know me? he asks them. “Truly I say to you, no generation of the people that are among you will know me.” In other words, Jesus tells them that they are strangers to him. The next day, they ask him about Heaven, and he laughs at them again. Forget about Heaven, he says. No mortal will go there. In response, the disciples “did not find a word to say.”

No wonder, for Jesus has just denied what is said to have been his sole mission on earth, the salvation of humankind. Later, he relents, a little: he says that some few mortals may be admitted to Heaven. The text is hard to read here, but it appears that this elect is limited to the Gnostics.

Jesus’ dealings with the disciples occupy about half of the surviving pages of the Gospel of Judas. The rest consists of a lecture that Jesus gives on cosmology—an account quite different from the Bible’s. Briefly, the real God did not create the earth, but he spawned an angel, who created thousands of other angels. Twelve “aeons” and seventy-two “luminaries” also came into existence, and each luminary was supplied with five firmaments, for a total of three hundred and sixty. This cosmos, as grand as it sounds, is described by Jesus as “corruption,” but apparently it is not as bad as the earth, which was brought into being by a violent demiurge, Nebro, and his stupid assistant, Saklas. The text goes on in this vein. N. T. Wright, in his book “Judas and the Gospel of Jesus: Have We Missed the Truth about Christianity?” (2006), says that as a churchman—he is the Bishop of Durham—he often gets letters that sound like the Judas gospel’s explanation of the universe: “Some are handwritten, in which case they are mostly in green ink. Some are typewritten, page after page of interminable cosmological speculation, with increasing amounts of block capitals and underlinings.”

What use could this bizarre document be to modern Christians? Plenty. Many American religious thinkers are more liberal than their churches. They wish that Christianity were more open—not a stone wall of doctrine. To these people, the Gospel of Judas was a gift. As with the other Gnostic gospels, its mere existence showed that there was no such thing as fixed doctrine, or that there wasn’t at the beginning.

That implicit endorsement of tolerance was probably what American scholars valued most in the Judas gospel, but the discovery gave them something else as well: righteous glee. What a joy to have an ancient document in which the man singled out in the Bible as Christianity’s foremost enemy turns out, arguably, to be Christ’s best friend. Hooray! The higher-ups don’t know everything! This was also the appeal of the new gospel to the political left. For people who claimed that the world was ruled by groups that controlled by marginalizing other groups, the Gospel of Judas was like a keystone being hammered into place. Men had silenced women, colonialists had silenced the colonized, and now we saw the Christian Church establishing itself by silencing other Christian voices.

The gospel’s enthusiasts had a narrower political purpose, too. The most important fact about Judas, apart from his betrayal of Jesus, is his connection with anti-Semitism. Almost since the death of Christ, Judas has been held up by Christians as a symbol of the Jews: their supposed deviousness, their lust for money, and other racial vices. The Bible scholar Louis Painchaud has said that the current fad for rehabilitating Judas is a consequence of collective guilt over these slanders and, above all, over the Holocaust. This must be true, at least in part. For anyone seeking to defend and protect the Jews, disproving Judas’s guilt would seem a good place to start, and here was an ancient gospel that appeared to support such a revision.

A number of people made special efforts to see that these lessons were learned. The restoration, translation, and publication of the Gospel of Judas were paid for, in large measure, by the National Geographic Society. This was an extremely expensive project, and the society wanted the gospel valued accordingly—that is, as a bombshell. In the same month, April of 2006, that the society published the first English translation, it also aired a television special and brought out a book—Herbert Krosney’s “The Lost Gospel: The Quest for the Gospel of Judas Iscariot”—proclaiming the document’s utterly revolutionary character. “It could create a crisis of faith,” one expert said on the TV show. In both that show and the Krosney book, a lot of sensationalist formulas—the voice from the beyond, the race against time, the some may call it treason—get a vigorous workout.

The trumpet calls were not confined to the mass media. Even the gospel’s translators may have felt the need to augment its revisionist credentials. When Jesus, in the gospel, tells the disciples that no mortal, or almost none, will be saved, one assumes that Judas will be an exception, and that’s what National Geographic’s translators said in the first English edition. But then a number of other scholars took a look at the Coptic text and objected that this was a misreading. The translators must have seen their point, because in the second edition of their version, published last year, the line has been changed—to mean the opposite. Jesus now says to Judas, “You will not ascend on high” to join those in Heaven. In other passages, too, the second edition tells a widely different story from the first.

In fairness, no expert can tell us exactly what the Coptic said. That is not just because of the terrible condition of the codex; even when the words are there, they are often enigmatic. But, as April DeConick, a professor of Biblical studies at Rice University, pointed out in the Times in 2007, there was a troubling consistency to a number of the mistranslations in the first edition: they improved Judas’s image. If the gospel was truly the earth-shaking document that the National Geographic Society claimed it was—if it promoted Judas from villain to hero—then to have him denied admission to Heaven would be decidedly awkward.