Hey, don't get flaming other religions, people. Jews have more in common with Muslims than Christians do, then again, they actually follow their religion better than Christians do. Apparently, Christians, Jews and Muslims are not allowed to eat the meat of a pig. A long time ago, Jews were being persecuted, and when they were pretending to be Christians to get out of persecution, the Christians began to eat pork to differentiate themselves from the Jews. The Jews would not eat pork.
That's why we have Christians eating pork while Muslims and Jews don't. And to answer ray's comments, we do believe that the Christians and Jews believe in God, but they associate partners with him. We still believe that you share the belief of one God, but you have different ideas of how to worship him. We never said you are polytheists, just that you made claims that God has a son.
Now, if you think that these three religions believe in different Gods, how did Christianity and Judaism get into the Qur'an? Aren't they totally different religions? I think not. They have the same roots, but the Bible, the Torah and the Psalms were changed, and parts of them were lost. And furthermore, how could all three religions have almost all the Prophets of God associated with them? Sure, Judaism rejects Jesus ad Mohammed, while Christianity rejects Mohammed, but before those two, we all share the belief of the Prophets. Also, the Prophet Abraham built the Ka'bah, the oldest mosque in the world. That must mean that he was a believer in God. And if he was the ancestor of all the Prophets to come, then they must've been believing in the same God as he did.
I think of Christianity as an 'upgrade' of Judaism. After all, Jesus was sent to the Jews to establish their religion when they were swerving to evil. And when the rest of the world began to go wrong, the Prophet Muhammad attempted to change it. He did succeed in changing the Arabs from cold-hearted barbarians to real humans with plenty of decency in their hearts.
So, Islam was esssentially an 'upgrade' to Christianity. It was brought to the world. If you were already a Christian at the time, you should've been racing to Islam. The mere similarity of the prophet Jesus (Arabic: Isa) should've had Christians converting to Islam on the double. After all, it was a change for the better.
So, I think we should begin to highlight the similarities between the three religions now.