Verse 4. The minister of God. The servant of God. He is appointed by God to do his will, and to execute his purposes.

To thee. For your benefit.

For good. That is, to protect you in your rights; to vindicate your name, person, or property; and to guard your liberty, and secure to you the rewards of your industry. The magistrate is not appointed directly to reward men, but they practically furnish a reward by protecting and defending them, and securing to them the interests of justice.

If thou do that, etc. That is, if any citizen should do evil. Be afraid. Fear the just vengeance of the laws.

For he beareth not the sword in vain. The sword is an instrument of punishment, as well as an emblem of war. Princes were accustomed to wear a sword as an emblem of their authority; and the sword was often used for the purpose of beheading, or otherwise punishing the guilty. The meaning of the apostle is, that he does not wear this badge of authority as an unmeaning show, but that it will be used to execute the lairs. As this is the design of the power entrusted to him, and as he will exercise his authority, men should be influenced by fear to keep the law, even if there were no better motive.

A revenger, etc. In Ro 12:19, vengeance is said to belong to God. Yet he executes his vengeance by means of subordinate agents. It belongs to him to take vengeance by direct judgments, by the plague, famine, sickness, or earthquakes; by the appointment of magistrates; or by letting loose the passions of men to prey upon each other. When a magistrate inflicts punishment on the guilty, it is to be regarded as the act of God taking vengeance by him; and on this principle only is it right for a judge to condemn a man to death. It is not because one man has by nature any right over the life of another, or because society has any right collectively which it has not as individuals; but because God gave life, and because he has chosen to take it away when crime is committed, by the appointment of magistrates, and not by coming forth himself visibly to execute the laws. Where human laws fail, however, he often takes vengeance into his own hands; and by the plague, or some signal judgments, sweeps the guilty into eternity.

To execute wrath. For an explanation of the word wrath, See Barnes "Ro 1:18".

It denotes here punishment, or the just execution of the laws. It may be remarked that this verse is an incidental proof of the propriety of capital punishment. The sword was undoubtedly an instrument for this purpose, and the apostle mentions its use without any remark of disapprobation. He enjoins subjection to those who wear the sword, that is, to those who execute the laws by that; and evidently intends to speak of the magistrate with the sword, or in inflicting capital punishment, as having received the appointment of God. The tendency of society now is not to too sanguinary laws. It is rather to forget that God has doomed the murderer to death; and though humanity should be consulted in the execution of the laws, yet there is no humanity in suffering the murderer to live to infest society, and endanger many lives, in the place of his own, which was forfeited to justice. Far better that one murderer should die, than that he should be suffered to live, to imbrue his hands perhaps in the blood of many who are innocent. But the authority of God has settled this question, (Ge 9:5,6) and it is neither right nor safe for a community to disregard his solemn decisions. See Blackstone's Commentaries, vol. iv. p.8, [9. ]