What role does the historical Jesus play in our faith today? I have consisted resisted images of Jesus predicting an end to the world because Jesus of the Gospels does not. Of that I am quite confident, although I've changed my mind about many thing for which I was once confident.
However, it seems Paul's letters are a much more reliable source of what the historical Jesus thought, and Paul thought the world was coming to an end–e.g., no reason to get married because it is happening so soon. Perhaps the Gospels served as a rebuttal to Paul–who never saw Jesus in the flesh–but my understanding is that this is not the case.
Jesus wrote nothing down and neither did any of his closest followers. That is an undeniable fact. There is a phrase "the post Easter Jesus" that is usually employed by folks who claim that not just the ministry of Jesus, but the Spirit of Jesus continued on past his death. The problem with this understanding for me is differentiating between (1) the holy spirit (2) post Easter Jesus and (3) the eminent God with us. Sort of a Trinity without a Distinction.