Eleanor: Look, dude, this isn't your fault. You've been teaching him ethics for half an hour, and he's been evil since... the beginning of time.
Chidi: Oh! Maybe the reason Michael can't latch onto the ideas is because he's immortal. Look, look. If you live forever, then ethics don't matter to you because, basically, there's no consequences for your actions. You tell a lie, who cares? Wait a few trillion years, the guilt will fade. Before I can teach Michael to be good, I have to force him to think about what we used to think about: that life has an end, and therefore our actions have meaning.