The most scholarly attempt that has ever been made to determine the historical origins of Christianity is currently underway. It is called “The Jesus Project,” it has scholars ranging from deeply historicist to deeply mythicist, and it is dedicated to going wherever the evidence leads. Its first conference was held in December 2008. Its meetings are open to the public and will be held roughly every nine months for five years. It will publish the papers presented at its conferences regularly through Prometheus Books. The world eagerly await its conclusions.
1 The reason I say “pre-crucifixion Jesus” is because I won't rule out the possibility of “visions,” but such a methodology—being indistinguishable (at least from the outside) from hallucinations or even one's personal imaginings—places Christianity on equal ground with every other “mythological history” in the world.
2 Jesus’s Alleged Crucifixion: Circa 33 CE. Time frame within which the various gospels were written: Mark: 70-105 CE, Matthew: 90-110 CE, Luke: 95-140 CE, John: 90-140 CE. These ranges represent the best estimates of mainstream scholarship and there is not enough data concerning the gospels for us to narrow these ranges.
4 Jesus does say many things that are easily taken out of context—millennia later. The term “Son of Man” was a colloquial expression at the time which meant “I, myself.” The term “Son of God” meant simply a holy man. “Your sins are forgiven you,” was something priests would say, and it meant simply, “I stand witness before God that you have repented”—a practice that should be not at all unfamiliar to anyone who has heard of the sacrament of confession or attended a healing by faith. Are these priests and ministers claiming to be God? No. But they are standing as representatives of God—and the Jesus character saw himself as doing exactly the same. Tobin is indispensable for going over these matters in depth on his website, and thus, as always, making the knowledge of mainline scholarship easily accessible to everyone:
5 All alleged references to Jesus (like those in Josephus) have been shown to be either forgeries or irrelevant (the authors referring to later followers of a Jesus figure and not being in a position to know how the movement actually started). Some Christians have tried to claim that the forgeries are only partially forgeries, but it is generally appreciated by scholars that they are actually total forgeries: http://www.geocities.com/paulntobin/sources.html