In this post I am going to briefly summarize Bart Erhman's book 'Did Jesus Exist?' and his reasoning for thinking that there was an historical man named Jesus who was crucified. Erhman does not think that Jesus was God or the earliest Christians thought Jesus was God either but these are side points since his goal is to show what he thinks to be overwhelming evidence that a guy name Jesus existed. Therefore, it should be clear his argument is not for the orthodox belief of Jesus but a different still historical Jesus.
Non-Christian Sources
One non-Christian source the people believed in a historical Jesus is Pliny the Younger who was the governor of the Roman province of Bithynia-Pontus in what is now Turkey. He wrote a letter in 112 A.D and Erhamn summarizes it, "Pliny learned from reliable sources that Christians (illegally) gathered together in the early morning. He provides us with some important information about the group: they included people from a variety of socioeconomic levels, and they are meals together of common food. Pliny may tell the emperor this because of rumors, which we hear from other later sources, that Christians committed cannibalism. (They did after all, eat the flesh of the Son of God and drink his blood.) Moreover, Pliny informs the emperor, the Christians "sing hymns to Christ as to a god."" (Non-Christian Sources for the life of Jesus, P 52). This is important because this means that there were people who believed in Christ about 80 years after Jesus lived and therefore, those people would be in great position to know if Jesus actually did exist.
Another non-Christian source is Tacitus who was a high-ranking Roman officials and Tacitus says, "Nero falsely accused those...the populace called Christians. The author of this name, Christ, was put to death by the procurator, Pontius Pilate, while Tiberius was emperor..." (P 55). Here we have a person who is the perfect position to know if a man name Jesus existed and then was executed and since he does claim this to be true then we should also think it is very plausible.
Flavius Josephus wrote The Antiquities of the Jews in 93 A.D. Now, there is reason to suspect part of what Josephus wrote was altered but there is a reasonable guess to what would have been the original and Erhman states it this way, "At this time there appeared Jesus, a wise man. He was a doer of startling deeds, a teacher of people who receive the truth with pleasure. And he gained a following both among many Jews and among many Greek origin. When Pilate, because of an accusation made by the leading men among us, condemned him to the cross, those who had loved him previously did not cease to do so. And up until this very day the tribe of Christians, named after him, has not died out."(P 61). Now, with Josephus we are getting closer to the time Christ lived and therefore, have more reason to trust what he wrote to be true, meaning that there was a guy named Christ condemn to the cross that a group of people called Christians followed.
This is a very brief summary of the non-Christian sources that we have that indicated a man name Jesus lived and was crucified. Given even these brief accounts the most plausible belief is not Christ never lived but that at very least there was a person named Jesus Christ who some worshiped and followed that was crucified.
The Gospels as Historical Sources
One does not simply have to just take the non-Christian sources as the only evidence that Jesus existed. Christian sources, even the New Testament, can and should count as evidence for the proposition that Jesus existed and was crucified. While it is common to think of the New Testament as one piece of literature it is important to remember that New Testament is a collection of books and letters. It would be more accurate to call the New Testament a Holy Library rather than a Holy Book. This means that each book of the New Testament that has an independent author can contribute to the cumulative case that Jesus existed and was crucified. It is important that the authors are independent because if Mark, Luke, Matthew, and John all wrote from the same source then these four gospels would not be independent authors all confirming that same event but one author stating something happened. When examining any event it is important to have multiple people confirm said event if we want strong justification for believing the event. Erhman begins with the gospel of Mark, "Our earliest Gospel account of Jesus's life is probably Mark's, usually dated--by conservative and liberal scholars of the New Testament alike--to around 70 CE...for now we are interested in the brute fact that within forty years or so of Jesus (alleged) life, we have a relatively full account of many of the things he said and did and of his death by crucifixion." (The Gospels as Historical Sources, P 75). The important note here is that the Gospel of Mark is within 40 years of Jesus life meaning if Jesus did not exist than people would surely know this. Here I think it is important to know that people of antiquity were not less intelligent than people today, many had less education but still there would be plenty of educated people refuting the claims by Mark yet best to my knowledge there is no one refuting Jesus existed.
Erhman goes on to explain why Matthew and Luke can still be counted towards the cumulative case despite access and using some of Mark's material, "These Gospels were probably written ten or fifteen years after Mark, and so by the year 80 or 85 we have at least three independent accounts of Jesus's life (since an umber of the accounts of both Matthew and Luke are independent of Mark), all within a generation or so of Jesus himself, assuming he lived." (P 76) The important note here is that Luke and Matthew have some accounts of Jesus that cannot be traced back to Mark hence they are independent accounts of Jesus. There is also the gospel of John which is written radically different than the synoptic gospels. John gospel was written around 90-95 A.D. which means that we have four independent accounts of Jesus's life and death.
Erhman wraps up the accounts of Jesus that are closest to the time Jesus existed by saying, "For a historian these provide a wealth of materials to work with, quite unusual for accounts of anyone, literally anyone, from the ancient world. This alone seems sufficient to show that Jesus existed but this is not all we have. There are more sources that also provide evidence but writing about that is for a different day.
Work Cited
Ehrman, Bart D. Did Jesus Exist?: The Historical Argument for Jesus of Nazareth. New York: HarperOne, 2012. Print.