Yvain isn't a big enough self-promoter to link to this, but I liked it a lot and I think you will too.
I feel like you could make a pretty good rationalist children's book, consisting only of a series of stories in which a protagonist is forced to draw an increasingly unpalatable conclusion, under increasingly hard circumstances. Show the pain of the struggle, and make a virtue out of the triumph.
Well, if you believe some versions of Christianity, Jesus possesses a whole stack of supernatural powers. He can apparently duplicate bread and fish, convert water to wine, manipulate the surface tension of water, coax aquatic life to concentrate on a particular side of a boat, and heal most any form of sickness or injury he feels like. Oh, and if he calls it in upstairs he can resurrect the dead.
Anyways, it seems that the obvious thing would be to attempt to perform a sampling of these miracles and observe the results. Simple theorem :
If this man can perform the miracles of Jesus, then he is Jesus
He can perform miracles
He is Jesus
Modus Ponens FTW.
Course, it isn't that simple. It's always possible that those supernatural powers are getting spread around like Halloween candy, so being able to perform miracles doesn't actually prove anything. (weren't his Disciples able to heal the sick as well, allegedly?) And "knowing" you did something is difficult if you are hallucinating all the time.
The scientific method applied to God was not looked upon favorably in those times (or many thereafter). The specific reason in the Bible that Jesus did not throw himself down from the cliff or turn stones into bread was to not "test God." Therefore any miraculous evidence would probably constitute a test. The situation is like Omega appearing and offering tantalizing amounts of utility if only a complicated (but tractable) hypothetical situation is correctly solved, with the additional condition that using rational thought processes causes immediate failure.
In fact, I should probably post a detailed description of FBDT (Faith-Based Decision Theory) that beats the pants off of TDT and other rational decision theories.
And "knowing" you did something is difficult if you are hallucinating all the time.
OTOH, I never hallucinate. I might be that sick, that in fact I hallucinate all the time and not knowing this, be cause I am never sane enough to even recognize I have hallucinations sometimes.
This is a Christ's point of view. A Christian just knows, that one of those Christs was the real one. Most probably the first one, also known as "the real one".
It's a great story, though.
EDIT: I should wrote "A Christian just knows" inside quotation marks. He thinks he knows. (As we all always do. We think we know, and sometimes we actually do know.)
If Jesus could see the entirety of history, then he could see whether he is the first "Jesus Christ". Given that the extra Christs are all explained by delusional patients copying the first Christ, this would be some sort of evidence (to himself) whether he is the real one.
Counterpoint: as Satan explains, it's all a hallucination anyway.
Well, if the Jesus of the story is reasoning from the evidence favoring his being the first Jesus, the position is going to take a substantial hit.
As Jesus is supposed to have risen from the dead and be immortal, I still don't think the hit is that strong.