How does the 'mythicist' use the belief systems of the Marcionites and other early Christian sectarians against Christianity? It seems that they want to make an appeal to common sense. If Jesus wasn't really a human being, they reason, the 'average person' who only nominally holds to the 'truth' of the Bible will come over to the side of 'reason' and join those laughing at the foolishness of organized religion. I happen to believe that this strategy is misguided. Nevertheless we have to come to accept that things are what they are.
From my perspective at least, I don't see the 'mythicist' argument as a danger to anyone's faith. The reality is that outside of American evangelical circles, the 'historical Jesus' is really superfluous to the function of the liturgy. One can almost still see the stitches that were used to sew the idea that Jesus was a man to the original core understanding that he was a divine being. I am not saying this as someone who 'wants to believe' that God came down to earth during Pilate's governing of ancient Palestine. I couldn't care less either way. The real point is that the liturgy is unmistakably rooted in the divine Jesus. It's just religious people and atheists are too stupid to see the actual reality of what is essential to Christianity.
If Jesus was a wholly human leader of the Christian faith what becomes of the Eucharist? It becomes an elaborate exercise in reverential platitudes which are ultimately meaningless. Yet if one slides the scales in the other direction and moves toward the Marcionite formulation and acknowledge that Jesus was wholly divine - how does anything change? The orthodox will tell you that Jesus 'needs to be human' to have the Passion make sense but that's utter nonsense. Surely the Marcionites had a functioning explanation of how a wholly divine Jesus Chrestos fit into a narrative where someone human gets nailed to the Cross. We just no longer know what the Marcionite logos was.
I think I have a sense of how the original Marcionite interpretation reconciled a wholly divine Jesus with a crucified human sacrifice. The divine Jesus goes into people and transforms their nature from something earthly into something heavenly. It wasn't that the Marcionites thought the Roman-Jewish conspiracy hung a phantom from the Cross. This is the parodistic propaganda developed by the Church Fathers to embarrass their adversaries. We just happen to have only one side of the story available to us.
Yet look at the very ancient tradition still preserved in the Islamic pseudepigraphal literature where someone else ends up crucified in Jesus's place. Christian believers can only see the notion of a crucified Judas as an 'attack' on the true beliefs of the Church. Nevertheless Irenaeus intimates that many early Christian believers managed to 'get along' without Jesus on the Cross. Indeed if contemporary Christians managed to get out and meet some of the one and half billion Muslims in the world, the idea of an 'uncrucified' Jesus has nothing to do with disrespecting the head of the Church.
It all then comes down to a single question - why take an interest in the idea of a divine being coming down from heaven in the fifteenth year of Tiberius's rule if you might not believe that such a thing is possible? The answer is that the study of ancient religions shouldn't be inflexibly rooted in 'historical facts.' This is something like selecting the woman you are going to marry based on her ability to wrestle. The 'facts' don't determine the outcome of whether a religion is successful any more than they do which candidate wins the general election. Religion and politics are all about 'belief' because these are things that matter to people. It is not a question then of whether or not we should believe that a divine hypostasis came down to earth in 30 CE but finally coming to terms with why it was that this message rooted in myth was so successful in 70 CE and beyond.
The answer is quite simple and straightforward and I doubt very much either the haters or the pious are likely to grasp it - the gospel narrative was only a vehicle for the establishment of the Eucharist. A myth was necessarily to establish the notion that eating flesh and blood could change one's yetser. This is why Christians are still called notsrim by Jews to this day (at least in books). Of course myths change and eventually the myth of a historical Jesus was developed. This was likely encouraged by the authorities at least in part because of the overwhelming appeal of the message of the notsrim on Jewish revolutionaries (see the conclusion of Clement of Alexandria's Quis Dives Salvetur). But that's a whole other story.
And they all lived happily ever after ...
