[Tree of Liberty]

I'd even settle for scientific proof that he lived.

Flavius Josephus, a non-religious Jew and pre-eminant historian of Roman rule in Israel, accounts for Jesus' existance. Also, I know of no contemporary that denied He lived.

That might not be "scientific" for you in that there's no known DNA remenants, but could such proof be shown of you after 2000 years?

[eclectic]

Flavius Josephus, a non-religious Jew and pre-eminant historian of Roman rule in Israel, accounts for Jesus' existance

Not exactly. The manuscript that includes reference to Jesus is believed to be a later altered version and this reference does not appear in other manuscripts