I want someone to explain Islam to me?

Ok, I try to not be racist, or a bigot whatever you want to call it, but if Islam is such a peaceful religion why are there so many Muslims who call Americans "infidels" and want to kill us? Please no hateful comments, I really want to understand. But everytime I see a Muslim or someone wearing a turban I suddenly become very afraid of that person. They want people like me and my children to die just because we don't believe in their religion!