Evidence of the Bible's Validity

[Cato]

Be careful, if the prediction and result are authored at the same time it is not a fulfilled prophecy.

I think you mean unreliable? I don't know I'm not following here.

Maybe an example. Let's say a book is written stating that Joseph Smith foretold Kennedy's assassination. Both the prediction and the event are in the past. Did Joseph Smith really predict Kennedy's assassination or is it more likely that the story of the prediction is a fabrication? There's no prophecy unless there is some independent evidence prior to the assassination corroborating the claim that Smith made the prediction.