Why go after a corrupted copy if you have the original?
The reason why Christianity and Islam were able to prosper is because they took the Holy text, corrupted it, and missionized it to the world.
How are we different?
The most important difference between Judaism and other religions is the revelation itself. All false religions began with one man who claimed to have received a message from G-d. This one man was either rejected or accepted by some in his generation. Judaism is different. The revelation of our religion was witnessed by 600,000 men (three million if you count women and children). As the verse says "...Not with our forefathers did HaShem seal this covenant, but with us - we who are here, all of us alive today. Face to Face did HaShem speak with you on the mountain, from amid the fire..."(Deuteronomy 5:3). During the Sinai revelation, there was not a single man who did not believe that this indeed is G-d's revelation. The whole nation witnessed the ten plagues of Egypt, passed through the split sea, and was nurtured by the miraculous Manna for forty years. NO other claim of revelation has come even close to what Judaism claims.
Common denominator of monotheistic religions.
The fundamental beliefs of major monotheistic religions are the following:
Christianity - Jesus is the son of G-d, while Moses was a prophet of G-d.
Islam - Both, Muhammad and Moses were prophets of G-d .
Judaism - Moses was a prophet of G-d, while Muhammad and Jesus were false prophets.
Christians do not accept Muhammad as a prophet of G-d, while Muslims do not accept Jesus as the son of G-d. Both religions, however, accept Moses as the prophet of G-d. The multitude of Christians and Muslims support the Jewish claim in the following way: Christians face 1.5 billion Muslims who reject their fundamentals, while Muslims face 2.3 billion Christians who reject their fundamentals. Therefore, Muslims support the Jews in that Jesus is not G-d's son, while Christians in that Muhammad was not a prophet. At the same time, Jews have the support of Christian and Muslim that Moses was a prophet of G-d, who has revealed the Holy Torah.
Religions of Peace?
Christianity and Islam both claim to be the religions of peace, and yet both have been involved in a massive religious massacre. The Christians have orchestrated the Inquisition and the Holocaust, while Muslims the Armenian Genocide. Certain Christian and Muslim groups are the first to misquote the Talmud (or quote it out of context) and accuse the Jews of evil, while history itself is pointing a finger back at them.
False statements in the Qu'ran.
Here are just a few examples.
"And Jews say Ezra is the son of Allah, and Christians say Messiah is the son of Allah....(Quran 9:30)" Where in the Jewish scripture or any other Jewish literature does it say the Ezra is the son of G-d? You will not find it, because it is not true.
"At length she brought the (babe-Jesus) to her people, carrying him (in her arms). They said: 'O Mary! truly an amazing thing hast thou brought! O sister of Aaron! Thy father was not a man of evil, nor thy mother a woman unchaste!'" (Qur'an 19:27-28)Was Mary (the mother of Jesus) the sister of Aaron? This would only be possible if she lived for 1,500 years.
Missing chapters of the Qur'an during Muhammad's lifetime?
It is related by Sahih Al-Bukhari - al jaami 6:501 "I asked Ubai bin Ka'b, "O Abu AlMundhir! Your brother, Ibn Mas'ud said so-and-so (i.e., the two Mu'awwidh-at do not belong to the Qur'an)." Ubai said, "I asked Allah's Apostle about them, and he said "They have been revealed to me, and I have recited them (as a part of the Qur'an)." If during Muhammad's time there were already two chapters missing from certain versions of the Qur'an, what can we expect today?