I never understood why people always portray Death as evil. As this post said, he is the definition of neutrality. If you believe in some sort of heaven or hell, he's the middle, he doesn't have a side. He either does stuff (theoretically) for his job or for his benefit. He doesn't "take sides" so he's not a threat.
10 Best 'Supernatural' Quotes from 'Devil's Bargain' (13x13
Quote from Supernatural 13x13 │ Lucifer (reading Bible): Would you look at the... Wrong. That's wrong. Does anybody fact-check this stuff? I mean, that's... (a moment later) Dad's always stealing my best lines, man. #Supernatural #Lucifer #Quotes
To be fair, do not commit adultery is part of the 10 commandments...