There is a certain tendency for people like Scott Atran to attribute religious violence to anything other than violent religious teaching. Well, the connection between beliefs and actions has recently been demonstrated in the arrest of a Norweigan Black Metal musician, who is apparently one of Breivik’s “Knights Templar”.
Note the term “Black Metal”. Ever since Heavy Metal got started, there has been an arms race to produce lyrics that are more evil, and therefore more hardcore, than the rivals – quickly reaching outright satanism, celebrating mass-murderers and so forth. Black Metal is the stage beyond Death Metal, where the lyrics of Death Metal are taken seriously – the only way of outbidding the others is to turn to actual evil: neo-Nazism, murder etc.
The Exile has an able discussion of it, even though you have to deal with their tiresome politics at the end. In other words, its no accident that the person arrested wasn’t a folk-singer or a composer of patriotic ballads.
Beliefs matter.