Juanita Jean, pretty much sums up how many Americans view terrorism. When a muslim commits an act of terrorism it is viewed as part of a muslim conspiracy. But when a christian commits an act of terrorism it is viewed as the act of a loner and nut-job. Personally, I don't see the difference. Neither is acting completely alone with no input from anyone else, but to consider either one as representative of their stated religion is also wrong.
Terrorists are all vicious criminals regardless of their religion (or lack of it) and no one is born to be a terrorist. It is a behavior that is learned from experiences and from listening to others (and those others may not even realize they are helping to create a terrorist). When we demonize those who we disagree with and talk as though they are less than human, then we may well be creating a future terrorist. The Norwegian terrorist was not a lone nut. He learned his beliefs and justified his behavior by reading and listening to others -- just as all terrorists do.