You have people that believe their religion is superior and anyone not following their religion is a pig, killing them will earn you a place in heaven.
We go to war fearing death, ducking from bullets whilst trying to get a shot off, we wake up scared thinking we may die today, they wake up and smile and hope that if they die they take a few with them.
If 15-25% are extremist they may not act on there views but support the view that also makes them extremists and easily turn to killing in the future. They may also encourage, fund or like what is happening. 15-25% is 300 million people.
Last night I watched a video of Indian Muslims who are upset that some of their mosks are being pulled down by the extreme muslims, a woman who is 40 odd with a her child standing next to her said she and 100,000 others are willing to go to Iraq and form a human chain around the mosks, if they die she said it will have been worth it as the mosk is more important than her life or her family and children......to me although she is not killing this is some what of an extreme view on the value of life, if a simple family woman can feel like this, i can see how easily a young man can kill.
I have not read their bible but if what those videos say is true that their bible says things about killing us (the infidels), that we must be converted or killed and they believe this. Then are not all muslims that say they are muslim hold the same beliefs of the extremist. I cant call myself a Christian and say I dont believe Jesus was on earth or that his mothers name was Mary. I have to believe in my whole religion if i wont to call myself a Christian. So again I have not read their bible just going off the video where the guys claims to have read it and says their bibles says XYZ, if true and you call yourself a muslim then you believe in these extreme views, you may not act on these views but you deep down believe them.
Sadly unless the moderate Muslims classify themselves differently, stop certain practices to differentiate themselves from the extremists this will end in a world war, this will make westerners stop buying from business's who are owned by muslims, this will create random bashings all of which will create more violence on both sides.