Here's a quote from a historian who was once just like all of you in your core beliefs: Bart Erhman, the James A. Gray Distinguished Professor and Chair of the Department of Religious Studies at the University of North Carolina at Chapel Hill:
"Let me begin by explaining in simple terms what it is that historians do. Historians try to establish to the best of their ability what probably happened in the past. We can't really know the past because the past is done with. We think we know that past in some instances because we have such good evidence for what happened in the past, but in other cases we don't know, and in some cases we just have to throw up our hands in despair.
It is relatively certain that Bill Clinton won the election in 1996. It may be somewhat less clear who won the election next time. It's pretty clear that Shakespeare wrote his plays, but there's considerable debate. Why? It was hundreds of years ago, and scholars come up with alternative opinions. It's probable that Caesar crossed the Rubicon, but we don't have a lot of eyewitness testimony. Historians try to establish levels of probability of what happened in the past. Some things are absolutely certain, some are probable, some are possible, some are "maybe," some are "probably not."
What kinds of evidence do scholars look for when trying to establish probabilities in the past? Well, the best kind of evidence, of course, consists of contemporary accounts; people who were close to the time of the events themselves. Ultimately, if you don't have a source that goes back to the time period itself, then you don't have a reliable source. There are only two sources of information for past events: either stories that actually happened based on, ultimately, eyewitness accounts or stories that have been made up. Those are the only two kinds of stories you have from the past -- either things that happened or things that were made up.
To determine which things are the things that happened, you want contemporary accounts, things that are close to the time of the events themselves, and it helps if you have a lot of these accounts. The more the merrier! You want lots of contemporary accounts, and you want these accounts to be independent of one another. You don't want different accounts to have collaborated with one another; you want accounts that are independently attesting the results. Moreover, even though you want accounts that are independent of one another, that are not collaborated, you want accounts that corroborate one another; accounts that are consistent in what they have to say about the subject. Moreover, finally, you want sources that are not biased toward the subject matter. You want accounts that are disinterested. You want lots of them, you want them independent from one another, yet you want them to be consistent with one another.
What do we have with the Gospels of the New Testament? Well, unfortunately we're not as well off as we would like to be. We'd like to be extremely well off because the Gospels tell us about Jesus, and they are our best sources for Jesus. But how good are they as historical sources? I'm not questioning whether they're valuable as theological sources or sources for religious information. But how good are they as historical sources?
Unfortunately, they're not as good as we would like. The Gospels were written 35 to 65 years after Jesus' death -- 35 or 65 years after his death, not by people who were eyewitnesses, but by people living later. The Gospels were written by highly literate, trained, Greek-speaking Christians of the second and third generation. They're not written by Jesus' Aramaic-speaking followers. They're written by people living 30, 40, 50, 60 years later. Where did these people get their information from? I should point out that the Gospels say they're written by Matthew, Mark, Luke, and John. But that's just in your English Bible. That's the title of these Gospels, but whoever wrote the Gospel of Matthew didn't call it the Gospel of Matthew. Whoever wrote the Gospel of Matthew simply wrote his Gospel, and somebody later said it's the Gospel according to Matthew. Somebody later is telling you who wrote it. The titles are later additions. These are not eyewitness accounts. So where did they get their stories from?
After the days of Jesus, people started telling stories about him in order to convert others to the faith. They were trying to convert both Jews and Gentiles. How do you convert somebody to stop worshipping their God and to start worshipping Jesus? You have to tell stories about Jesus. So you convert somebody on the basis of the stories you tell. That person converts somebody who converts somebody who converts somebody, and all along the line people are telling stories.
The way it works is this: I'm a businessman in Ephesus, and somebody comes to town and tells me stories about Jesus, and on the basis of these stories I hear, I convert. I tell my wife these stories. She converts. She tells the next-door neighbor the stories. She converts. She tells her husband the stories. He converts. He goes on a business trip to Rome, and he tells people there the stories. They convert. Those people who've heard the stories in Rome, where did they hear them from? They heard them from the guy who lived next door to me. Well, was he there to see these things happen? No. Where'd he hear them from? He heard them from his wife. Where did his wife hear them from? Was she there? No. She heard them from my wife. Where did my wife hear them from? She heard them from me. Well, where did I hear them from? I wasn't there either.
Stories are in circulation year after year after year, and as a result of that, the stories get changed. How do we know that the stories got changed in the process of transmission? We know the stories got changed because there are numerous differences in our accounts that cannot be reconciled with one another. You don't need to take my word for this; simply look yourself. I tell my students that the reason we don't notice there's so many differences in the Gospels is because we read the Gospels vertically, from top to bottom. You start at the top of Mark, you read through to the bottom, you start at the top of Matthew, read it through the bottom, sounds a lot like Mark, then you read Luke top to bottom, sounds a lot like Matthew and Mark, read John, a little bit different, sounds about the same. The reason is because we're reading them vertically.
The way to see differences in the Gospels is to read them horizontally. Read one story in Matthew, then the same story in Mark, and compare your two stories and see what you come up with. You come up with major differences. Just take the death of Jesus. What day did Jesus die on and what time of day? Did he die on the day before the Passover meal was eaten, as John explicitly says, or did he die after it was eaten, as Mark explicitly says? Did he die at noon, as in John, or at 9 a.m., as in Mark? Did Jesus carry his cross the entire way himself or did Simon of Cyrene carry his cross? It depends which Gospel you read. Did both robbers mock Jesus on the cross or did only one of them mock him and the other come to his defense? It depends which Gospel you read. Did the curtain in the temple rip in half before Jesus died or after he died? It depends which Gospel you read.
Or take the accounts of the resurrection. Who went to the tomb on the third day? Was it Mary alone or was it Mary with other women? If it was Mary with other women, how many other women were there, which ones were they, and what were their names? Was the stone rolled away before they got there or not? What did they see in the tomb? Did they see a man, did they see two men, or did they see an angel? It depends which account you read. What were they told to tell the disciples? Were the disciples supposed to stay in Jerusalem and see Jesus there or were they to go to Galilee and see Jesus there? Did the women tell anyone or not? It depends which Gospel you read. Did the disciples never leave Jerusalem or did they immediately leave Jerusalem and go to Galilee? All of these depend on which account you read.
You have the same problems for all of the sources and all of our Gospels. These are not historically reliable accounts. The authors were not eyewitnesses; they're Greek-speaking Christians living 35 to 65 years after the events they narrate. The accounts that they narrate are based on oral traditions that have been in circulation for decades. Year after year Christians trying to convert others told them stories to convince them that Jesus was raised from the dead. These writers are telling stories, then, that Christians have been telling all these years. Many stories were invented, and most of the stories were changed. For that reason, these accounts are not as useful as we would like them to be for historical purposes. They're not contemporary, they're not disinterested, and they're not consistent."