The resolution source for this market will be a consensus of credible sources. I'm too skeptical to believe that a source is credible if that source claims any resurrection, let alone of a messiah. If a man who looks just like Jesus in the images showed up and performed all of the same miracles, I still wouldn't believe it. I wouldn't believe it if the Pope declared it true, or something claiming to be God announced…
I agree that almost anything I can think of would be more likely some kind of trick. Or in the most extreme examples I'd have to assume there's a good chance I was experiencing some kind of psychosis. So I'm not sure I could actually be convinced either. I suppose if I personally witnessed clearly impossible miracles being performed and multiple people I know and trust corroborated what I was seeing, that might do it.