Charles Ellicott Commentary Romans 13:4

"for he is a minister of God to thee for good. But if thou do that which is evil, be afraid; for he beareth not the sword in vain: for he is a minister of God, an avenger for wrath to him that doeth evil." — Romans 13:4 (ASV)

The sword.—Not apparently the dagger worn by the Roman emperors, but, in a strict sense, “the sword.” “To bear the sword” seems to be a recognized Greek phrase to express the power of the magistrates. It was carried before them in processions and on other important occasions.

It is clear from this passage that capital punishment is sanctioned by Scripture. At the same time, its abolition is not excluded, as the abolition of slavery was not excluded, if the gradual development of Christian principle should seem to demand it. Whether or not capital punishment ought to be abolished is a question for jurists, publicists, and statesmen. The theologian, as such, has no decision to give either way.