Hey. My understanding is that there is considerably diversity within Islam as there is considerable diversity within Christianity. As such, it is hard to make true generalisations across such a large (and diverse) group of people.

The religious practices of a group of people can often be tied up with cultural practices and the cultural practices of a comparatively small group of people can sometimes be mistaken for the religious practices of the whole group.

I think that there are some extremists (of all religions) who capture the majority of the media attention and thus the 'common sense' conception of the Islamic religion in the western world comes to be based on the activities of a few extremists. That would be like... Taking the kkk or those who think it is okay to murder abortionists to be representative of christianity. (Both are fairly clearly unfair overgeneralisations).

This website seems pretty good. I haven't had the time to read it all yet, but I probably will return to it:

http://www.religioustolerance.org/comp_isl_chr.htm

My notion of Islam being derived from Christianity as Christianity is derived from Judaism is as follows:

In the beginning there was the old testament. Those of the Jewish faith accept this as a religious text. And... My understanding is that those of Christian and Islamic faith also accept this as a religious / spiritual text (though for the latter two later religous texts 'trump' the old testament).

Then came the new testament. Those of the Jewish faith do not accept this as a religious text. Those of the christian faith accept this as their most important religious text, however. And my understanding is that those of muslim faith fairly much accept this as well, though they also consider this to be trumped by a later text.

(There are variations as to what is considered to be part of the new testament by different 'sects'. The Roman Catholic church accepts additional books to protestant churches, for example. It is fairly interesting to read about the politics involved in the decisions as to what writings got to be part of the new testament and which writings did not get to be part of the new testament. I have this funny feeling that the book of Judas will never make it in even though it is as authentic as the other books in the new testament: http://www.nationalgeographic.com/lostgospel/ )

And then along comes Mohammed and the Quiran. Jewish people don't accept this and neither do Christians. But Muslim people accept this as their most important religious text.

So... The later texts are typically considered to 'trump' what has gone before... And the differences between the religions (with respect to religious texts anyway) is a layering exercise... Kind of like this:

Old testament -> New testament -> Quiran.

People of Jewish faith get off the boat at stage one.
People of Christian faith get off the boat at stage two.
People of Islamic faith get off the boat at stage three.

And the mormons... Well... Instead of the Quiran they think that Joseph Smith found additional religious texts and thus you get the books of the mormon bible (which might be viewed as a layer on Christianity as Islam is). And for mormons... The books of the mormon bible trump what has gone before.

I hope this post is okay... It was in response to the thoughts of the person who started the thread and...

It is okay to learn about religions, right?

And all that was a way of deriving the interesting fact (that I didn't know) that people of Islamic faith don't believe that Jesus died on the cross (they believe he ascended straight to heaven) and thus the crucifix would not be an Islamic religious icon). Also... They are much stricter on their interpretation of 'Idols' hence the problem around depicting Mohamid in artistic (or cartoon) form...