To determine that a killing is murder, you first have to assume that the victim is a human being. Perhaps the author would argue that we should eliminate murder laws as well, because of their religious nature.
If you continued down that rabbit hole, I think you’d end up finding that all laws have a religious taint, and are not the business of the courts.
My suggestion holds for you as well.
As they should. If you believe that your rights come from gubmint, gubmint can grant or take them away at any time. If you believe your rights are God given, only He can take them away,
All laws are based on someone’s idea of morality.