That sounds as though it is an interesting book, Rev, with an interesting slant on Jesus' life history (legend, myth,....).

Maybe the shifting of the emphasis of Jesus as a Jew to Jesus as the sacrifice and saviour in fact led to the way that the early church encouraged absorption of existent religious myth into their own story of the life of Jesus. This quirk is evident in the date of celebration for Christmas, the Easter name and extraneous myths, the sacrifice of the god himself - plus heaps more. Paul was a Roman citizen and may have realised that the blending of these familiar ideas would help expand the acceptance and spread of the new religion into the Roman Empire.

The whole Mithras Myth bears a huge resemblance to Christian belief I think. None of that stems from the teachings of Jesus himself, the influence appears to be the other way.