The confusion over the resurrection has gone on so long it has become a self-sustaining muddle with a compelling question: how did this myth become the foundation stone for a religion, so unnecessarily? It is remarkable that with Islam we see the hidden spiritual attempts to recast monotheism without the liabilities of Christianity.
The question of the resurrection is not so impossible to solve but a scientific approach can equally confuse the issue. Ghosts can be real and people could have confused this with resurrection. A sense of the contact with the dead is a very widespread phenomenon, and the sense of resurrection might have arisen in this context. In a way the experience of Paul may show what’s really going on: he has an experience of an astral contact and this is confused with the idea of resurrection.
(There are many other interpretations, viz. Jesus didn’t actually die on the cross and escaped to India.)
Resurrection is a myth, but a powerful sense of presence from the dead is another question. Turning this into a myth was but a short step…