Here is Murray Rothbard:
The fact is that libertarianism is not and does not pretend to be a complete moral, or aesthetic theory; it is only a political theory, that is, the important subset of moral theory that deals with the proper role of violence in social life. Political theory deals with what is proper or improper for government to do….
Here is J. Gresham Machen:
There are vase departments of life with which [judges and juries] should have nothing whatever to do. They are exceeding their God-given function when they seek to enforce inward purity or purity of the individual life, since theirs is the business only of enforcing –and that in necessarily imperfect fashion — that part of righteousness which concerns the relations between man and man.
As I said in my consideration of Romans 13: “Notice that Paul does not use the specific words for righteousness (dikaios) and sin (hamartano), which would necessarily bring in the entirety of the moral law of God. Rather he uses the very general terms for good (agathos) and evil (kakos).”