In the Bible, Jesus Christ names 12 apostles to spread his gospel, and the early Christian church owes its rapid rise to their missionary zeal. Yet, for most of the Twelve, there's scant evidence of their existence outside of the New Testament.

In Apostle: Travels Among the Tombs of the Twelve, author Tom Bissell sets off to discover whether the Twelve Apostles were actual historical figures or merely characters in a fictional story. On the way, he walked for 500 miles along the Camino de Santiago pilgrim route in northern Spain, visited the place where Judas Iscariot reportedly hanged himself, and hunted in vain for a mysterious monastery in Kyrgyzstan where the bones of the Apostle Matthew are believed to be buried. It’s a journey full of false starts, dead ends, and unsolved riddles that leaves him as perplexed as when he began. (Discover why the Virgin Mary is the world's most powerful woman.)

Speaking from Vancouver, Bissell explains why one of the inspirations for his book was the Monty Python film Life of Brian and how his views of Christianity changed along the way.

If there had been a New York Times best-seller list in the first century A.D., which column should the New Testament have appeared in? Fiction or nonfiction?

I’m not sure if that is a distinction that would have made a lot of sense to anyone in the first century. There was no distinction between evangelistic propaganda and what the writers themselves believed to be true. From a modern viewpoint, it’s hard to see the Gospels as unvarnished, truthful accounts. The journalistic impulse didn’t exist back then. People’s partisan beliefs that magic and divinity were at work in the world were overriding. Today we would call it creative non-fiction, with the emphasis on “creative.”

You grew up a Catholic, but then had a crisis of faith. Wind the clock back and explain how that inspired you to write this book.

I did not have a crisis of faith so much as I just read a few books that made me realize, “Wow, none of this stuff is probably true in the way that I thought it was.” Yet I remained deeply interested in these stories in the Hebrew Bible and the New Testament. But I have to confess that the biggest inspiration for this book was the film Life of Brian—that scene where Brian is running from the Romans, jumps out of a tower, and lands in the middle of a marketplace full of all these gabbling prophets saying nonsense, and so just starts reciting random stuff and attracts an audience. After having grown up in Catholic school watching all these sanitized, educational Christian films, that segment of the film painted to me a more vivid, realistic, and psychologically believable portrait of the first century than anything I’d ever seen! [Laughs]

View Images Author Tom Bissell calls Monty Python's satirical film Life of Brian a "vivid, realistic, and psychologically believable portrait of the first century A.D." Photograph by AF Archive, Alamy

You say that, “Christianity’s special appeal is largely furnished by its claims of historical legitimacy….yet the existence of the faith’s most crucial eyewitnesses is uncertain.”

A couple of the names recorded in the New Testament are probably actual people. There was probably a Peter and a John, definitely a James (the brother of Jesus), and probably a Thomas. Beyond that, there’s nothing historical that verifies their existence other than the gospels themselves. So I think they’re a mixture of fact and fiction.

View Images Apostle: Travels Among the Tombs of the Twelve book cover Courtesy of Penguin Random House

One of the great mysteries of early Christian history is that we know a fair amount about Paul and we know that James, the brother of Jesus, was a real person. Yet neither of them is a member of the Twelve. So you have these 12 people who were the first followers of Jesus, yet there’s nothing about them in any secular source. Paul’s letters mention both Peter and John, though, which suggests they were historical figures and not just names.

You begin your search in Jerusalem for the final resting place of Judas Iscariot, whom you call the “electromagnet of wickedness.” Tell us about that journey—and whether you believe Judas was a real historical character.

That is a very thorny question. According to tradition, though scripture is not clear on this, Judas hanged himself in a place called Hakeldama in the Hinnom Valley, which is this rocky, desert-like valley in the southern part of Jerusalem. When you go there, it really does feel like it’s a cursed place. That’s the power of these stories. You feel the centuries of hatred and disgust for this person who betrayed Jesus.

View Images According to legend Judas Iscariot hanged himself at Akeldama, also known as the Field of Blood, near Jerusalem. "When you go there, it really does feel like it’s a cursed place," says Bissell. Photograph by Duby Tal, Alamy

As to whether Judas was real, I think it’s probably true that Jesus was betrayed by someone. Whether or not his name was Judas is a much more difficult question. I suspect the broad outlines of the Judas story, as the gospel writers outlined it, is probably fictional. In a lot of the other Jesus stories, the gospel writers seem to be singing from the same hymn sheet. But with Judas, I think they had much less raw material to work with, so they all treated it in their own way. This suggests to me that he was more a fictional character than actual person.

In 2006, a team of translators and scholars working for National Geographic published the so-called lost “Gospel of Judas.” Did this shed any further light on the subject?

The Gospel of Judas was an artifact of Sethian Christianity, a very confrontational form of non-mainstream Christianity in the second century. They believed Judas walked a slightly different path than the conventional Judas. Their Judas is simultaneously an object of condemnation and also illumination. They believed in a completely different God from the proto-orthodox Christians of their time. The Sethian Christians hated the apostolic authority model that other Christians followed. There were a lot of really diverse forms of Christianity floating around in the first two hundred years of the faith. And some of them were really odd.

View Images The existence of James, Jesus' elder brother (shown here in a painting by El Greco), is supported by historical evidence—but contradicts the idea of a "Virgin Birth." Photograph by Heritage Image Partnership Ltd, Alamy

Kyrgyzstan is not a place most of us associate with Bible stories. But you went there looking for the tomb of Matthew. Tell us about your trip—and whether you found it.

Today, central Asia does not seem to be the most Christian-accommodating part of the world, but until the Middle Ages there were a large number of Christians. They were not Roman or Greek Christians. They were Middle Eastern Christians, who kept migrating eastward.

According to a medieval map from Spain, Matthew’s relics were buried in a place called the Monastery of Armenian Brotherhood, which was believed to be on the shore of Lake Issyk-Kul, this beautiful body of water in the middle of the Kyrgyzstan Mountains. A Russian archaeologist claimed to have found it in 2006, so I went off to search for it. I soon discovered that there had never been an Armenian monastery there, only a 19th-century Russian monastery. But it was one of my favorite journeys because it was really hard to find and was one of the most enchanting places I have ever been, even though my quest to find St Matthew's relics came to an anti-climactic end. [Laughs]

You call the Apostle James a “particularly elusive character.” In 2002, an ossuary surfaced in Israel, which appeared to confirm his identity. Is there any truth to it?

We know James, the brother of Jesus, was a real person. He’s mentioned by Flavius Josephus, a first-century Jewish historian. Some people say that the ossuary is real but the inscription, which says "James, the Brother of Jesus" in Aramaic, is not. No one has found his body, but he was clearly a well-known figure in the first century, who turns up an awful lot in early Christian writing. The fact that Josephus and others regarded the Roman destruction of Jerusalem as divine revenge for the death of James, who was killed circa A.D 66 right before the Jewish revolt against Rome, tells you everything you need to know about how significant he was.

I’ve not seen the ossuary and I’m not a trained archaeologist, but I’m perfectly willing to believe that James could have had a secreted away tomb, with an ossuary. His followers would almost certainly have given him a significant burial site. But the problem with James is that he confounds everything orthodox Christians accept about the virgin birth. If he were Jesus’s older brother, that’s a big problem right there because Mary was supposed to be a virgin. I suspect James was real, that there is a good chance he was the older brother of Jesus, and that he was the most important figure in first-century Christianity after Jesus. But the virgin birth does not make a heck of a lot of sense. The known laws of the universe don’t typically stop working. [Laughs]

View Images Each year, hundreds of thousands of pilgrims walk the 500-mile Camino de Santiago in northern Spain, which purportedly leads to the burial place of James. Photograph by Jennie Hart, Alamy

Did your journey end up convincing you of the historical veracity of the Apostles? Or just make you even more confused?

It didn’t make me either, really. One of my pet peeves is this notion that simply to believe in something is good. I have a real hard time accepting that because what if you believe in something monstrous? A lot of the beliefs that come out of the monotheistic Abrahamic religions are quite upsetting from a modern perspective. The way they treat women, the way children are viewed, the way authority is viewed—these don’t have much of a place in today’s secular society.

But I became much less hostile to Christianity over the course of this book. Anyone who enjoys opera or film or fiction doesn’t have a lot of call to question meaning drawn from religion. The search for meaning in words or images, these longings we have to be convinced, moved, or inspired by works of the imagination—all have way more in common with each other than not. The stories of the Twelve Apostles are a huge part of how the Western world decided to teach itself what is meant by community and story-telling and by truth, friendship, and loyalty.

I realized that getting mad at religious people for believing what they believe is a bit like getting mad at a rainstorm for making things wet. A better position is to try to find a place where we can all agree on the importance of meaning derived from literature or works of the imagination. I know it would insult most Christians to consider the New Testament as a work of the imagination. But I don’t mean that in the sense that it’s all fake, but rather in the sense of drawing consolation from another person’s attempt to order the universe. Maybe that it’s just a story is the best thing it can be.

This interview was edited for length and clarity.