Until 1945, most of what anyone knew about the Gnostics came from a bishop who wanted them gone. His name was Irenaeus, he ran the church in Lyons around the year 180, and he wrote five volumes explaining why these people were wrong. Scholars read him for their facts the way you might read a prosecutor’s closing argument to learn about the defendant.
Then a farmer dug up a jar near Nag Hammadi, and the defendants got to speak. I’ve spent a lot of time on this blog with what they said. I want to go back to the prosecutor now and ask a fair question: how good was his case?
The Man Behind the Book
Irenaeus wasn’t an armchair critic. According to Bart Ehrman, he was born around 130, probably grew up in Smyrna, studied in Rome, and became bishop of Lyons around 178. Elaine Pagels points out that his teacher Polycarp was burned alive, and that Irenaeus watched a mob turn on the Christians of his own city in the summer of 177. Christians there were beaten, stoned and thrown in prison.
So when he sat down to write, he was the leader of a battered community, and he saw the Gnostic teachers as one more threat to it. The title tells you where he stood. Ehrman renders it Refutation and Overthrow of What Is Falsely Called Gnosis, borrowing a phrase from 1 Timothy 6:20, where Paul warns against “what is falsely called knowledge.” Most people just call it Against Heresies.
He states his goal near the start, in the translation Pagels quotes. He wants to show “how absurd and inconsistent with the truth” the heretics’ statements are, so his readers can steer others away from “such an abyss of madness and of blasphemy against Christ.” That’s a man with a mission, and you should know it before you take anything from him.
What He Got Right
The surprise, at least for me, is how much of his reporting checks out. Irenaeus summarizes a myth in Book 1, chapter 29, with an invisible Father, a first Thought named Barbelo, and a fallen Wisdom who produces a defective creator. When the Secret Book of John turned up in Coptic, scholars recognized it.
In Meyer’s Nag Hammadi Scriptures, the introduction to Three Forms of First Thought calls part of its creation story “virtually identical” with the shorter Secret Book of John and with Irenaeus, whose account it dates to around 175 or 180. Bentley Layton is a bit more careful. He says the resemblance “is not perfect,” which suggests Irenaeus had a different version of the text in front of him.
If you’ve read my guide to the Apocryphon of John, that’s a striking thing to sit with. A hostile reader in Gaul got the outline right from a copy that doesn’t quite match any of ours.
Layton reads the bishop’s long summary of Ptolemy, a Valentinian teacher, as stitched together from several written works, which tells you Irenaeus had documents on his desk. Irenaeus also knew of a book called the Gospel of Truth, which he calls especially “full of blasphemy.”
Pagels notes that scholars still argue over whether it’s the same Gospel of Truth found at Nag Hammadi. Ehrman treats it as the same book. Either way, the bishop didn’t invent the people he was fighting. He read their books, and some of what he wrote down about them is the best record we have.
What He Bent
The trouble starts when he moves from describing to explaining. Take the charge of forgery. Irenaeus says the followers of Valentinus “put forth their own compositions, while boasting that they have more gospels than there really are.”
He backed his own four gospels with a famous argument, which Ehrman sums up this way: there are four corners of the earth and four winds, so there must be four gospels and no more. Most scholars now doubt that eyewitnesses wrote Matthew, Mark, Luke and John, as Pagels notes. The charge that other gospels used borrowed names cuts back at the bishop’s side too. I went through that argument in Are the Gnostic Gospels Just Late Forgeries?
Then there’s interpretation. Irenaeus said the Gnostics took the Bible apart and rebuilt it to suit themselves. Ehrman retells his image for it. Someone takes a beautiful mosaic of a king, rearranges the tiles into a dog, and says this is what the artist meant all along.
It’s a great line. But Ehrman also notes that Irenaeus read Leviticus’s food laws as being about kinds of people, which is the same allegorical move he mocked in others.
The moral charges are the shakiest. Irenaeus claims, for instance, that followers of a teacher named Carpocrates believed they had to experience every kind of deed, wicked ones included, to escape being reborn in another body. Layton is blunt about these reports: “It is difficult to judge the accuracy and fairness” of them.
Meanwhile, a lot of the Nag Hammadi library leans hard the other way, toward fasting and celibacy and suspicion of the passions. I covered that tension in Did the Gnostics Hate the Body?
The Problem He Couldn’t Solve
For me, the most revealing passages in Irenaeus are the ones where he admits nobody could tell the difference. Pagels shows how much this bothered him. The Valentinians recited the same creed as everyone else and sat in the same churches.
Irenaeus says they did “verbally confess one God,” but with private reservations, “saying one thing, and thinking another.” Most Christians, he complains, couldn’t distinguish their teaching from his, the way most people can’t tell cut glass from an emerald. He even wrote to Victor, the bishop of Rome, warning him that Gnostic writings by a priest named Florinus were circulating among the Roman congregations.
That detail changes the picture. These weren’t outsiders storming the gates. They were members, some of them clergy, who read the shared scriptures differently. The heresy hunter’s main job was drawing a line through his own congregation.
What the Defense Said Back
When the Nag Hammadi codices came out of the ground, it turned out the polemic ran both ways. The Revelation of Peter has the Savior describe church leaders this way, in Meyer’s translation:
“And there are others among those outside our number who call themselves bishops and deacons, as if they have received authority from God, but they bow before the judgment of the leaders. These people are dry canals.”
It’s a pretty good insult. A canal is built to carry water, and these ones have none. Meyer’s note suggests the image was adapted from the “dry springs” of 2 Peter, possibly for an Egyptian audience that knew canals.
So the Gnostics had their own name-calling, and their own claim to be the true church. Reading both sides together doesn’t hand the win to either one. What it does is show you two groups of Christians, both convinced they were faithful, arguing over the same Jesus. Only one of them got to decide which books were copied for the next fifteen centuries, a story I traced in Why Gnosticism Was Suppressed.
How to Read a Hostile Witness
Irenaeus is still worth reading. He’s the reason we can date some of these texts before 180, and he preserved summaries of systems that would otherwise be lost. Here are the questions I bring to him, and to anyone writing about a group they oppose.
Is he describing or explaining? His summaries of myths tend to hold up. His accounts of motives and morals don’t, because he couldn’t see inside anyone.
When he says what a text contains, give him some credit. When he says why people believed it, slow down.
Can I check this against their own words? For the Secret Book of John, you can. For Carpocrates, you mostly can’t. The claims you can’t check deserve a lighter grip.
Would he say the same thing about his own side? The mosaic charge fails this test, since he read scripture allegorically when it suited him. When a critic condemns a habit he shares, the complaint usually isn’t about the habit.
Who benefits if the reader believes him? Pagels makes a strong case that the fight over Gnosticism was also a fight over who had authority in the church. Irenaeus was a bishop arguing for the authority of bishops. That doesn’t make him wrong, but it tells you where to press.
Those questions work on plenty besides second-century bishops. Try them the next time you read a confident takedown of a religion or a movement written by someone who’s never been inside it. Then see if you can find a single page written by the people being described, and read that page first.
The Revelation of Peter, Meyer’s notes on it, and the editorial remark on Three Forms of First Thought are quoted from The Nag Hammadi Scriptures, edited by Marvin Meyer (HarperOne, 2010). The Irenaeus quotations and the material on Polycarp, Florinus and the Valentinian creed come from Elaine Pagels, The Gnostic Gospels (Random House, 1979), which uses older translations of Against Heresies. Layton’s remarks come from The Gnostic Scriptures, second edition, with David Brakke (Yale University Press, 2021). The Ehrman material is from his Lost Christianities course. 1 Timothy 6:20 is quoted from the NIV.
