Charles Ellicott Commentary Romans 13:5

"Wherefore [ye] must needs be in subjection, not only because of the wrath, but also for conscience` sake." — Romans 13:5 (ASV)

It follows, from this divine authority and title enjoyed by the magistrate, that he ought to be obeyed, not only from fear of the punishment that he is empowered to inflict, but also from the respect due to legitimate power. Of this respect conscience is the natural guardian.