The one thing that would disprove/prove Christianity for me would be when we discover another planet with intellegent life. I would assume that God would have visted this other planet as well and that they would have a similar story about a "Jesus" figure that taught the same things. I don't know if this would 100% disprove Christianity for me, as maybe "Jesus" could still visit this planet in the future, but it would for sure get me to re-think my beliefs.
The Bible was meant to be read in context, as a whole narrative, not in fragments.