There were also a number of false prophets whose predictions did not come to pass. The events that the authentic Prophets spoke about did come to pass -- such as the destruction of the Temple and its rebuilding etc.

Furthermore, I would say that the burden of proof is upon those who wish to argue that they were written by later authors. Let’s look at a far more contemporary situation by way of example. Let’s say I wish to argue that the plays of William Shakespeare were written by someone else, not by Will himself. (There are in fact those who argue this—see http://ise.uvic.ca/Library/SLT/drama/baconiana2.html). Furthermore, many of the plots and themes of his plays were borrowed from earlier sources—see http://shakespeare.about.com/od/shakespearessources/.

The Prophets were well known men and women. Their character and honesty were above reproach. If a later scribe would have written it and attributed it to the earlier Prophet, the plot would have been discovered instantly

If one does not accept this, that is his/her prerogative. However, the vast majority of Jews certainly did, and were willing to put their lives on the line for their beliefs. Would you be willing to put yours on the line that Shakespeare’s plays were really his? Probably not, because it does not mater to you that much. Jews were (and are) willing to give up their lives for our beliefs because they do matter to us. We regard them as the words of G-d. Would anyone who had doubts about that be willing to gives up their lives for a doubt?

In any event, belief in the words of the Prophets is the sixth of Maimonides’ Thirteen Principles of Faith: “I believe with prefect faith that all the words of the prophets are true.” Jews accept this as an article of faith without requiring proof, and we are all the better for it.