The fact that people dedicate lives to these books that are thousands of years old and have nothing to do with todays morality and thought is scary, and the exstremists find the verses that tell them to kill non believers and use them as justification. I thin Quran has these sword verses, which the jihadists use, but other muslims don't accept. But you can't just pick good and dispose of bad, and that's why these books (Quran and Bible) are worthless.
Here's a verse that I found:
"And slay them wherever ye find them, and drive them out of the places whence they drove you out, for persecution is worse than slaughter... and fight them until fitnah is no more, and religion is for Allah."
— Quran 2:191
Once again, I have nothing against muslims or any religious people, I just think that they should let go and not force it on children.