Dala and I bantered around about your question a bit today. I don't think either of us really have the credentials or the background knowledge to really discuss the idea substantially or authoritatively, but it was a fun conversation. We talked a bit about whether or not a cultural, political, and religious movement as long lasting, far reaching, and impactful as Christianity could exist if it was all centered around a person that didn't exist, how trustworthy oral traditions are in regards to historical accuracy, how close in geological and temporal history written documents about a man should be to be considered to be trustworthy, etc. You might be interested to know that similar questions have been brought up about other religious figures. In regards to Jesus though, the consensus is pretty much overwhelming that he did exist, there's evidence to suggest as much, but the true picture of who he is and what he may or may not have done is hard for us to ascertain to any concrete degree. As for me personally, I do believe that he existed and was a prophet.