The title is key here because Werner is not a bad person. He's just an orphan along with his sister who gets swept up in Nazi-mania. Through the book, he's largely left in the dark to the horrors and atrocities the Nazi military are committing though he suspects that something is off. This is a masterpiece of a novel and one that should instantly move to the top of anyone's TBR list if you haven't read it already.
All the Light We Cannot See was adapted this year into a Netflix limited series. I haven't seen the show yet but I fully intent to at some point in the near future.