Are Christians Supposed to Be Radical?

If you listen to the average news program it is not unusual to hear a commentator use the term radical to describe someone who is outside the mainstream when it comes to their beliefs or behaviors. Usually it is used to label someone as evil or dangerous based on their religious beliefs. In the case of Christianity, it is often used when describing believers who are more conservative of fundamentalist. Based on how the word radical is used, are Christians supposed to be radical according to the Bible?