I like people who draw up comparisons between Islam of today and Christianity of 600 years ago - despite the fact that for last 1400 years they have evolved in completely different enviroments, and the birth of Islam was very, very different from the birth of Christianity, they somehow come up with minor similarities and extrapolate on those.
Islam started as relatively unified theological work, used to actually gather people under a single banner. They sought to bring stability to greater Middle East, by sword. But alas! islam soon learned that it would be better to give the opponents a choice - bend or die. So they came up with delicate rules for the entire religion, which - warlikely - prevented abuse against fellow muslims but allowed for violence against pagans. All while keeping a discreetly neutral position towards elder religions of the same phylogenetic tree, namely Jewism and Christianity. This, of course, inevitably resulted in internal strife and finally civil wars and separations and stuff. You can witness it today by comparing Shia and Sunni.
Christianity, on the other hand, started as a bunch of obscure, hysterical, often violent sects which were pretty much underground. It took over 300 years - from the death of Christ and the formation of the new sects to the internal problems of Roman empire - for them to form even relatively binding consensus about things like holy trinity, flesh of god, killing, war, whatever. After this the Christianity quickly spread to Europe, of all places. I will not give you a rundown of Europe of 400ad to Europe 2006ad, but it's a complex mishmash which survived pretty much by interacting with Asia and North Africa, while different tribes were happily slaughtering each other for just and unjust reasons and just for fun and hell just for war! I started to type a brief history of Renessaince, Mameluks, Ottomans, Lutherians and **** but just gave up. The histories of the two are intervined yet so different from each other that direct comparison is pretty much impossible. Christianity is sect-and-interpretation-based, very flexible and tired religion. Islam is law-and-habit based and the only significant strife happened 1000 years ago. People would do well to try to judge the two religions by themselves or then just drown in the grey goo of cultural relativity.
People who follow the religion, though, are people and people don't really change. They will always be xenophobic and warlike.
Edit: OK two quick points and bad metaphores before I go to bed.
1. Bird and bat have wings. They are not closely related though, similarities do not always support close relativity.
2. Cultures with similar backgrounds can and will evolve differently because of different enviroments and humans guiding them.
3. Just because code A and code B have similar sequences it does not mean that they process them similarly
My long and badly written reply to inevitable backlash will come tomorrow. Sleep ist mein Freund.
