At different blogs, I've seen some rather shocking claims about what is and what isn't in the Koran.
For someone who claims to be interested in religion, I know very little about Islam. I don't even own a Koran. But it's easy enough to find one online, and just for the sake of curiousity and laziness, I did a search of the Koran text for three words; 'Jew', 'Christian', and 'Messiah'. There were 22 hits for 'Jew', 14 hits for 'Christian', and 9 hits for 'Messiah'. Here are some examples for the word 'Jew'.
[2.62] Surely those who believe, and those who are Jews, and the Christians, and the Sabians, whoever believes in Allah and the Last day and does good, they shall have their reward from their Lord, and there is no fear for them, nor shall they grieve.
[2.113] And the Jews say: The Christians do not follow anything (good) and the Christians say: The Jews do not follow anything (good) while they recite the (same) Book. Even thus say those who have no knowledge, like to what they say; so Allah shall judge between them on the day of resurrection in what they differ.[5.18] And the Jews and the Christians say: We are the sons of Allah and His beloved ones. Say: Why does He then chastise you for your faults? Nay, you are mortals from among those whom He has created, He forgives whom He pleases and chastises whom He pleases; and Allah's is the kingdom of the heavens and the earth and what is between them, and to Him is the eventual coming.
[5.69] Surely those who believe and those who are Jews and the Sabians and the Christians whoever believes in Allah and the last day and does good-- they shall have no fear nor shall they grieve.[5.82] Certainly you will find the most violent of people in enmity for those who believe (to be) the Jews and those who are polytheists, and you will certainly find the nearest in friendship to those who believe (to be) those who say: We are Christians; this is because there are priests and monks among them and because they do not behave proudly.
[22.17] Surely those who believe and those who are Jews and the Sabeans and the Christians and the Magians and those who associate (others with Allah)-- surely Allah will decide between them on the day of resurrection; surely Allah is a witness over all things.
Christians and Jews are almost always mentioned together. (The verse here that excited me the most is the last one mentioning the Magians. I know more about dead religions than I do about the largest religion on the planet, not that this is saying much.) The verse about Christians not behaving so proudly is an ironic one. So why didn't I include the verse where Mohammad calls the Jews and the Christians infidels worthy of death? Because, it seems, it isn't there. If it is, will somebody please show it to me? I wouldn't say Mohammed's attitude is always consistent; he seems a little miffed from time to time, but the worst thing he does is say that their fate it is up to Allah.
I think people are drawing the frightening quotes they are using from other Islamic sources. This really isn't fair. I could quote what different popes or Martin Luther and the reformers had to say about the Jews, and it would be equally as frightening, if not more.
And lastly, because of my ecumenical nature, lets see what Mohammed had to say about Christ.
[4.157] And their saying: Surely we have killed the Messiah, Isa son of Marium, the apostle of Allah; and they did not kill him nor did they crucify him, but it appeared to them so (like Isa) and most surely those who differ therein are only in a doubt about it; they have no knowledge respecting it, but only follow a conjecture, and they killed him not for sure.
[4.171] O followers of the Book! do not exceed the limits in your religion, and do not speak (lies) against Allah, but (speak) the truth; the Messiah, Isa son of Marium is only an apostle of Allah and His Word which He communicated to Marium and a spirit from Him; believe therefore in Allah and His apostles, and say not, Three. Desist, it is better for you; Allah is only one God; far be It from His glory that He should have a son, whatever is in the heavens and whatever is in the earth is His, and Allah is sufficient for a Protector.
[4.172] The Messiah does by no means disdain that he should be a servant of Allah, nor do the angels who are near to Him, and whoever disdains His service and is proud, He will gather them all together to Himself.
Mohammad accepts the virgin birth, but his fierce monotheism rejects the diety of Christ, and the doctrine of the Trinity. Of course, a Jew would accept none of this. I think it would be very interesting to study exactly which Christian sects Mohammed came into contact with. As well, it would be interesting to study his interaction with Jewish, Mandaean, Zoroastrian, and Manichaean groups.
I've had the Muslem attitude towards the Koran explained to me in the following manner. The Koran is the Logos, the Word of God. This seems a little different than the Christian approach to it's scriptures. In Christianity, the Logos, the Word of God, is Jesus Christ. If you think about this for a bit, it becomes obvious why defiling the Koran in any way horrifies a Moslem. And I have to admit that I think the Moslem structure just makes more sense.