Religion or belief systems - what have you - are not the problem. Having the freedom to choose what you believe or don't believe is one of the reasons my country was founded in the first place and I would defend anyone's right to subscribe to whatever suits his/her fancy.
Fanatics, on the other hand, regardless of motivation, are another thing entirely. And, I'm talking about the people who speed past the pale of energetic enthusiasm and run straight into dangerous/lethal acts against other people; abortion clinic bombers, wacko cult leaders demanding mass suicides, and airborne terrorists. These people are bullies and the only way to handle a bully is to stand up to them. Yes, they scare me, but not to the point of running away.