Prophecy? That doesn't sound rational to me. I thought you said this was rational.
Prophecy is simply the documented prediction of a specific set of circumstances or events. Prophetic fulfillment means that the prediction came true. Can you think of any other words in a modern context which have an intellectually positive connotation for this same process?
That's right, in science, we would call this a hypothesis. If the outcome is as predicted by the hypothesis, then we would say the hypothesis is true within a degree of certainty (okay, technically we would disprove the null hypotheses within a degree of certainty, because scientism believes we cannot know anything for absolute certainty, but you get the idea).
If one hypothesis and set of outcomes points to the existence of some truth, it would be reasonable believe that it might exist. If hundreds of hypotheses all points to the same outcome and the same truth, we would be fools to disbelieve the preponderance of evidence.
You can say this whole project is based on the "hypotheses" of Old Testament "theolotists", with New Testament authors reviewing the findings, if that helps you to examine the evidence more fairly and with less preconceived bias.
Central to the Catholic Christian claim is that God, in His desire to have a personal relationship with us, chose to reveal himself in a way no human person or group could control or manipulate - the "prediction" of extremely specific sets of historical circumstances and outcomes, predating their precise occurance in many cases by hundreds of years.
Couldn't the original prophecies be manipulated post-hoc (after the fact)?
In almost all cases, we have copies of the old testament texts which predate any reason or opportunity for their manipulation (such as the Dead Sea scrolls).
What about the presence of miracles and other things I have never experienced? These cannot possibly be accurate, and so the texts cannot be reliable historical accounts.
Just because you have never experienced something, nor has anyone with whom you have personally interacted, does that mean that it cannot exist? Miracles are documented in all cases as exactly that - extreme departures from the everyday lived experience of the people recording the events. That is why the authors were so compelled to the record them, because these experience were so out of the ordinary. If a research physicist experienced a highly unusual and unexpected phenomenon, and then chose to document it, would we consider his entire work flawed because of the presence of this odd experience in his findings? Certainly not; we would assume, based on his good intentions, that he was documenting something of genuine interest to his knowledge community. We can argue about what exactly it was he experienced; however, the intention of the researcher was to document something which he believed truly happened. The same can be said of the intentions of the authors of the testaments, both old and new.
