I would guess because they don't believe Jesus was the messiah.

Why do most Christians reject the Koran? Understand that and you'll understand why Jews reject your holy book.

Because Jesus doesn't fulfill the Messiah requirements listed in the Tanakh. http://www.evilbible.com/jesus_false.htm

Because the New Testament denies the fundamental beliefs of Judaism (like the need to observe the Torah laws forever and the identity of the Messiah).

several reasons, which i am sure have already been said, but I will ist anyway: 1) Jesus did not meet the requirements of the messiah to them. 2) Much of what is in the new testament completely clashes with their beliefs. Mind you, I am talking about from their point of view. Imagine if you made up a game, played it for 1000 years and someone came along without your authorization and changed the rules. Then had the nerve to tell you that it is you who don't know your own rules. You would not find them credible at all and would likely be offended they even suggested such a thing. 3) Think about how christians view the book of mormon. No jew would take the new tetstament any more seriously than christians take the almost 2000 year after the fact additions to their religion the book of mormon adds.

One big reason is that until very recently many Christians tried to force their beliefs on Jews. This was especially true in Europe. In America, however, Christians learned to tell Jews that being Jewish is a good thing, you should maintain your Jewish culture and language, but that you should also reconsider why so many Jewish people--starting with the Apostles--believed that Jesus of Nazareth was the Jewish Messiah. There's a new book out called The Jewish Trinity that has a boatload of new proofs from the Hebrew Old Testament that were never understood before. You can read about it at <www.yoel.info>.

It's ironic since Jesus Christ Himself was a Jew. But the Jews didn't see Him as the Messiah, therefore do not believe in the New Testament. The Jews are still waiting for 'their' Messiah. But the Bible tells us that the day will come when the Jews recognize Jesus as the Christ... and so far Bible prophecies have been 100% accurate.

Dear Friends. The real answer is very simple. It is a thing of logic, since men have discernment to understand that the Religious representatives of Judaism know the Jesuchrist is not the Messiah they are waiting and for a reason of intelligence that manifest us the Mesiah have to give proofs he is coming in name of God and with one purpose only, that the mankind don't be deceived for a false Messiah of Jews. The prior is the reason of why the Judaism don't accept the Jesuchrist as the Messiah they are waiting. The Jesuchrist never gave proofs he was the Messiah of Jews. It is better to manifest the writers of New Testament didn't know which are those proofs the Messiah carry with him to give proofs the Jesus was the Messiah. Now If you understand that the God of Jews in Egypt was the Lion of Judah and his HOUSE was the Great Pyramid, then exist the possibility you discern this Messiah you are waiting is coming in name of the Constructor of Great Pyramid, the so mentioned Biblical Pharaoh of Egypt. The Great Pyramid is the God of Mankind and the Messiah of Jews is the real Envoy of the Constructor of Pharaoh, the real name of the Great Pyramid, the reason of intelligence why Moses never named the name of the Biblical Pharaoh. This was the Pharaoh that Moses manifested the Jews wanted to escape from Egypt since they considered themselves slaves of conscience from a STONE in thinking the Messiah will make act of presence on Earth. They committed a big mistake and from that day the Jews cast aside the Scientific Dogma of Faith from Pharaoh, from the Great Pyramid, the entire mankind come down on DARK until today and that stupid action is just the reason of why the Scientists and Governments on Earth don't believe me that I am the Envoy of Constructor of Great Pyramid for the surviving this mankind today, and only by the day to be too late to wail the entire mankind will cry and will wail the stupiditity their parents today.

Because, since they had written the "Old" Testament, they knew exactly what it meant and what the prophecies were - so they knew more than anyone else that Jesus was not, in fact, the messiah.

Because in the NT you have Paul running around with these new "revelations" that were used by Christians to turn the religion completely away from its supposed "roots" Let's see some of the atrocious differences: Trinity Death Going To Heaven Or Hell Immediately After Death Messiah's Role In The Grand Scheme Of The Book Sunday Worship Christmas & Easter Torah Abandonment End Times Rapture Messianic Kingdom Meaning Behind "Spirit" Now the sad thing is that most of those mentioned above are not even supported by the NT but Christians do an outstanding job making it seem like such. With that and the fact that this religion uses it for these contrary doctrines (to Judaism, the SUPPOSED foundation) then it's no wonder at all why the Jews RIGHTFULLY reject the NT As someone else stated it's the same way Christians reject Mormonism, Adventism, Jehovah's Witnesses, Islam though they all claim to come from Christianity as their foundation but with new twist...I mean "revelations".