I hope my comments earlier were not taken as an attack on you, for I certainly did not mean as such.  I did attack Foucault and Strauss, but the point of this was to state that, in an article about whether a figure who appears in ancient texts is historical or fictional, it is pointless to cite people who think that history is fiction (and that figures in texts are therefore nothing more than figures).  And I will say it absolutely does matter to Christianity whether Jesus existed as a historically or not.  In short, the doctrine of the Incarnation holds that God became truly man, whilst remaining truly God, and thus established in his being a communion between man and God, allowing eternal life (because God is life, and so without union with him there is only death).  This incarnational principle appears in doctrines of both the Eucharist and the Church.  It also appears concerning the redemption of mankind.  In religion before Christianity men offered sacrifices to atone for sin or to appease divine powers, however these sacrifices were never enough because of the infinite gap between God's magi sty and man's finitude, and for this reason some religions sought to make the greatest sacrifice, offering up humans as victims – but even this will not do (as I am sure you can see).  Hence the Eucharistic institution and the crucifixion, understood incarnationally, are examples of a man (Jesus) offering God (Jesus) to God; and, lastly, that this happened during the greatest human sin (deicide) makes real the claim that God will never abandon his creation no matter how far the fall.  This was all very brief, but with your philosophical background I am sure you can understand, and if you never got this in your classes on religion then you were done a great disservice.