Alex Pareene makes an important point about alleged Oslo shooter Anders Breivik identifying as a Christian:
He's a sick perversion of Christianity, sure. But if he "doesn't count" as a Christian solely because no one this evil should "count" as a Christian (which is [Bill] O'Reilly's other argument -- "no one believing in Jesus commits mass murder," he said) then no terrorist should "count" as a representative of his faith.
O'Reilly's argument is that Christianity as a faith shouldn't be tarred by the actions of a terrorist. But by that logic, neither should Muslims be held accountable for the actions of a tiny minority that mostly kills other Muslims. But barring some sort of Dave Chappelle-like ethnic/religious draft process, Breivik is properly identified as a Christian. All the more reason not to engage in guilt by association when other religions are involved.
I would also add that the irony of O'Reilly's protest is that the anti-Muslim bloggers whom Breivik admired are constantly arguing that the terrorists' interpretation of Islam is the true interpretation, a view that has filtered into the mainstream of the Republican Party. O'Reilly should take a minute and imagine how absolutely beside himself he would be if a non-trivial number of opinion elites were committed to the idea that mass slaughter in the service of religion was the true interpretation of Christianity.