You cannot do this with Christ because there is no evidence that he was ever a fictional character created by someone's imagination.
Yet another trap, tec. I forget how it went: "The absense of evidence is not evidence of absense", or so...
No one can prove Jesus is fictional, thus Jesus is real...We do not have evidence of the fictional nature of Zeuss either...
EDIT: (so we don't go again down the rabbit hole) If looked at from both sides there is no evidence (I mean pictures, corroborating accounts, piece of cloth, whatever) of the existence or of the non-existence of Jesus. All we have is absence of evidence of both, which in turn is not evidence of either..