A Very Lutheran Serial Killer?: Reports that Dennis Rader—the suburban family man and Cub Scout leader accused of leading a double life as the BTK serial killer—was also active in his Lutheran church have already caused some Christians to express shock. But maybe it’s not so surprising after all. The idea that a Christian is simul iustus et peccator—at the same time justified by faith and a sinner—lies at the heart of Martin Luther's theology. It would also seem to be at least one way of comprehending the horrible deeds of Rader, not to mention all the (hopefully less gruesome) sins which the rest of us commit every day.