Jesus Christ has made a cameo in hundreds of pop culture places, from The Da Vinci Code to South Park. But, although the character of Jesus has certainly been fictionalized, satirized and mythologized over the centuries, the vast majority of Americans still maintain that he was a historical figure. More than nine out of 10 adults say Jesus Christ was a real person who actually lived (92%).
Barna Research Group, April 1, 2015. https://www.barna.org/barna-update/culture/714-what-do-americans-believe-about-jesus-5-popular-beliefs#.VSQ4Bc7maow
That Jesus was a historical figure who actually existed is a difficult fact to deny. My guess is that the reason a very small percentage claimed that he didn't exist is either because of apathy or ignorance; either they don't really care one way or the other, or they simply don't know and have just assumed that he was made up. In any case, Barna's recent survey results reveal that Jesus' existence will probably not need to be argued when you talk to your skeptic friends about Jesus.
That said, Barna's survey also revealed that people have very different ideas about what Jesus was like. Differing opinions on topics ranging from Jesus divinity to whether or not he ever "sinned" (insert your own definition of sin here) mean that even though we mostly agree that Jesus existed, we don't all agree on what he was actually like. This is fertile ground for the Christian to do some thinking: how do we know what Jesus is like? How can I be sure that what I think I know about Jesus can actually be trusted? If Jesus really existed, what type of a person was he?
The first challenge the Christian will face is moving people from the point of acknowledging Jesus existence to actually inquiry of what he was about. This is a bigger challenge than it seems. You might wonder to yourself why in the world someone wouldn't care what Jesus was really like, but insert any other historical figure into the discussion and ask yourself...do you care? How many history books have you read recently? How many historical figures have you inquired about? The truth is that most people in America know approximately the same number of facts about Jesus as they do about Napoleon or Alexander the Great. We know their nationality, a little bit about their story and what they did, and that's it. Not only do we have a very limited knowledge of who they actually are, but most of us feel no pressing need to dig any further. Why should we feel any differently about Jesus?
A second challenge the Christian will face is how we actually go about finding out more about Jesus. The easy answer is "the Bible", and more specifically, the four accounts of Jesus life, Matthew, Mark, Luke, and John. Simple enough on the surface, but it raises a third challenge: how do we know that those accounts can be trusted? After all, we know going in that the Gospel writers were clearly biased. The writers were either one of Jesus twelve disciples themselves (Matthew, John), a close follower of Jesus and probably very close acquaintance of a disciple of Jesus (Mark with Peter), or a very close acquaintance to the famous Apostle Paul (Luke).
These three challenges become the central challenges for the Christian looking to engage the world with what they actually believe, and I think ought to be of primary importance to anyone who claims that Jesus actually exists. First, why should I care about Jesus? Second, where do I find out more about him? Third, how do I know that those accounts can be trusted?
Unless we have an answer to those questions, I think that whatever we believe about Jesus will be little more than speculation.