A list of reasons to answer: no.
- If the Passion story was really the key of every gospel, then we would have a such story not so strongly theologically oriented to make the point that Jesus is the "Christ"/"king of the Jews". Contra factum that we don't have a Marcionite Passion story. We don't know if Pilate figured in a Marcionite Passion story. We don't know if the only "crucifixion" in the Evangelion was the Transfiguration episode itself.
- The episodes of healings vehicle a point that finds in themselves a good midrashical explanation, without requiring a prediction of the Passion story.
- If the Passion story was merely a theodicy for the tragedy of the 70 CE, then the same Passion story ceases ipso facto to be the mere translation on the earth of a celestial crucifixion happened in outer space. Evidence that a such translation happened is the use of the term "archontes" to mean the Jewish chiefs of the people (and/or Herod), while the real political archontes were the Romans. The primary impulse was a naïve identification of earthly archontes, not at all a theodicy for the facts of the 70 CE. Indeed, this naivety of the way by which the demons were euhemerized on the earth as Jewish or Roman authorities is not different at all from the way by which other mythological deities were euhemerized on the earth (Attis reduced to a shepard, Osiris reduced to a Pharaon, Helios to a Elijah or a Samson, etc). A mythicist can't have both the things: the euhemerization of a celestial myth and the theodicy for the facts of the 70 CE.
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