Were the original prophecies of the Messiah altered? Jews state that Jesus did not fulfill all of the prophecies realting to the Messiah. They also claim that the followers of Jesus in the early ages sincerely believed he was the Messiah, and altered the Old Testament to suit their needs.
It is true that some Jews claim that Jesus did not fulfill all the prophecies relating to the Messiah. At the recent debate that we at ARS sponsored in June in Chicago, the Jewish Rabbi Shmuley Boteach claimed, specifically, that the Hebrew scripture prophesies a Messiah who will usher in a period of world peace. He does not see this world peace ushered in at the time of the Messiah and therefore says Jesus certainly did not fulfill this prophecy. My response is that Shmuley misinterprets these prophecies (such as Isaiah 2:4, to give an example). Jesus fulfilled this prophecy when he established the church, in which swords are indeed turned into plowshares. In the church it is true that those who were avowed and unrepentant enemies are made into brothers and sisters. I have seen this "world peace" created by the Christian Church in South Africa with my own eyes. Nevertheless, it is true that many Jews who choose to reject Christianity will make such a claim that Jesus did in fact NOT fulfill all the prophecies of the Messiah.
However, as for the claim that the Christians altered the Old Testament to suit their needs, this is clearly a completely spurious claim. Even today, the Jews use the exact same Hebrew Old Testament that Christian use (although the order of the books is different in Jewish Bibles, which is not relevant to the question). Even if Christians wanted to alter the Old Testament, it would be literally impossible. The Jews created the dominant Hebrew text of the Old Testament, known as the Masoretic Text, right up until the 11th and twelfth centuries–a time for which we have dozens of extant manuscripts. Is someone claiming that the Jews altered their own Old Testament to make it appear that Jesus fulfilled the messianic prophecies? Besides, we have significant OT manuscripts from before the life of Jesus. The Dead Sea Scrolls clearly could not be changed by believers in Jesus because almost all of them were written down before he was even born. This charge that the Christian Church somehow changed the Old Testament scriptures in order to make a stronger case that Jesus is the Messiah prophesied in the Old Testament is complete nonsense. It is proved wrong both by common sense and by the facts of the matter.
Now, perhaps some Jews will claim that certain TRANSLATIONS of the Hebrew scripture into other languages are made with prejudice toward Christainity. Certainly this is a possibility. The solution for us is to work with the original Hebrew language, and to consider using a translation of the Old Testament done by Jewish scholars. I believe that if we do this, none of the messianic prophecies which are used to show that Jesus is the Messiah will be sufficiently changed to alter the final conclusion. I have done some of this research for myself. I have also read Jewish commentators on some of the messianic prophecies. My conclusion, based on an admittedly limited amount of research, is that I have not yet had to change any of my own personal conclusions with regard to messianic prophecies, although I have learned to understand better current and past Jewish perspectives about the Messiah. One quick example is that Isaiah 7:13-17 may very well be a prophecy, both about the Messiah, and about the circumstances in Judah in the time Isaiah wrote.
Note: given the nature of your question, I am very confident you are going to want to pick up a copy of the tribate "Judaism, Christianity, Islam, Which is the True Legacy of Abraham?" There were many comments made by all three participants which are relevant to your question. You can get a copy at www.ipibooks.com
John Oakes, PhD