Jesus Mythical and Real?

[TheLightWithin]

No, I'm saying the doctrine of the resurrection was the fundamental principle of Christianity – without that, as Paul saw, you have nothing but Jewish apocalyptic speculation.

That's 1 Corinthians isn't it - If Christ was not risen our faith was in vain?

When was Christianity ever not about the Resurrection?

That seems to be the core, more than any other doctrine. Enough so belief in that alone is Christianity, and everything else is commentary.
Otherwise why all the so called "heresies" - don't they all believe in the resurrection?