Did Jesus Exist?

Historian Bart Ehrman says yes:

In his book, Ehrman marshals all of the evidence proving the existence of Jesus, including the writings of the apostle Paul.
"Paul knew Jesus' brother, James, and he knew his closest disciple, Peter, and he tells us that he did," Ehrman says. "If Jesus didn't exist, you would think his brother would know about it, so I think Paul is probably pretty good evidence that Jesus at least existed," he says.
In Did Jesus Exist?, Ehrman builds a technical argument and shows that one of the reasons for knowing that Jesus existed is that if someone invented Jesus, they would not have created a messiah who was so easily overcome.
"The Messiah was supposed to overthrow the enemies – and so if you're going to make up a messiah, you'd make up a powerful messiah," he says. "You wouldn't make up somebody who was humiliated, tortured and the killed by the enemies."
So Jesus did exist, but who was he? Ehrman says when historians focus on the life of Jesus, they discover a Jesus who is completely different from the one portrayed by popular culture or by religious texts.
"The mythicists have some right things to say," Ehrman says. "The Gospels do portray Jesus in ways that are non-historical."

I guess the Catholic Church would argue that brother James deal.  It kind of messes with that Marian tradition.  I also found this portion to be very interesting:

When Raz asks Ehrman about his relationship to Jesus, Ehrman says that most of it is very historical but that Jesus teaches us valuable lessons.
"Jesus' teachings of love, and mercy and forgiveness, I think, really should dominate our lives," he says. "On the personal level, I agree with many of the ethical teachings of Jesus and I try to model my life on them, even though I don't agree with the apocalyptic framework in which they were put."

The radio segment went into more detail.  Ehrman said he had been a Christian, but had become agnostic.  While that was the case, he believed Jesus' teachings should be the guide to peoples' lives.  I'm very sympathetic to that position.