Thomas Aquinas

After the Apostle has shown that we must not remain in sin, and that we have the capacity for this, here he concludes with a moral exhortation. And concerning this he does three things: first, he sets forth the admonition; second, he assigns the reason, at the place, "for sin," etc.; third, he raises a question and resolves it, at the place, "What then? Shall we sin?" etc. Concerning the first he does two things: first he sets forth the admonition; second he expounds it, at the place, "that you should obey," etc.

He says therefore first: it has been said that our old man was crucified together with him, that the body of sin might be destroyed, by which it is given to be understood that the power of sin has been so diminished that it cannot have dominion over us. Therefore let not sin, for the rest, reign in your mortal body. But he does not say: let there be no sin in your mortal body, because as long as our body is mortal, that is, subject to the necessity of death, it cannot be that there is not sin in our body, that is, the tinder of sin. But since we have been freed by God from the reign of sin, we ought to strive that sin, having already lost its dominion in our body, should not recover it in us. And this is what he means when he says, "let not sin reign in your mortal body." And this indeed must be guarded against as long as we bear a mortal body, because it is said in Wisdom 9:15: "the corruptible body is a load upon the soul," etc.

Then, when he says, "that you should obey," etc., he expounds the aforesaid admonition. Concerning which it must be considered that sin reigns in man in two ways. In one way, through the interior consent of the mind. And removing this he says, "that you should obey the lusts thereof." For to obey, by the mind's consent, the lusts of sin, is for sin to reign in us. Ecclesiasticus 18:30: "Go not after your lusts." In the second way, sin reigns in us through the execution of the deed. And to exclude this he adds, "but neither yield you your members to sin," that is, to the tinder of sin, "as instruments of iniquity," that is, instruments for carrying out iniquity. For when man, through his members, carries out sin, he carries it out unto iniquity; and by this very act he seems to be fighting to restore the dominion of sin, which grows strong in us through the habit of sinning. Ezekiel 32:27: "they went down to hell with their weapons."

Then, when he says, "but present yourselves to God," etc., he exhorts to the contrary, namely that we should present ourselves to God. And first as to interior affection, when he says, "but present yourselves to God," namely that your mind should be subjected to him. Deuteronomy 10:12: "And now, Israel, what does the Lord your God require of you, but that you fear the Lord your God, and walk in his ways?" And this you ought to do as those who are alive from the dead, that is, as those brought back to the life of grace from the death of fault. For this is also why it is just that he who lives should now no longer live for himself, but for him who died for all, 2 Corinthians 5:15. Second, as to the exterior act, whence he says: "present your members to God," that is, for his service, "as instruments of justice," that is, certain instruments for carrying out justice, by which, namely, you may fight against the enemies of God. Ephesians, last chapter: "Put on the armor of God, that you may be able to stand against the deceits of the devil."

Then, when he says, "for sin," etc., he assigns the reason for the aforesaid admonition. For someone could excuse himself, alleging the dominion of sin, by which he might assert that he was hindered from observing the aforesaid admonition. This, therefore, the Apostle first excludes, saying, "for sin shall not have dominion over you," namely if you begin to resist sin and to present yourselves to God, according to that word of James 6:8: "Draw near to God, and he will draw near to you: resist the devil, and he will flee from you." As if to say: you are able to observe the aforesaid things for this reason, that you do not find sin having dominion over you, by which you could be drawn back; for we have been freed by Christ, according to that word of John 8:36: "if the Son shall make you free, you shall be free indeed."

Second, he makes clear what he had said, saying, "for you are not under the law, but under grace." Here it must be considered that he is not speaking here of the law only as regards the ceremonial precepts, but also as regards the moral precepts; and someone is said to be under this law in two ways. In one way, as one voluntarily subject to the observance of the law. And in this way even Christ was under the law, according to that word of Galatians 4:4: "made under the law"; because, namely, he observed the law, not only as regards the moral precepts, but also as regards the ceremonial precepts. But the faithful of Christ are indeed under the law in this way as regards the moral precepts, but not as regards the ceremonial precepts. In another way someone is said to be under the law as one compelled by the law; and in this sense he is said to be under the law who is compelled to observe the law not voluntarily out of love, but out of fear. Such a one, however, lacks grace, which, if it were present, would incline the will to the observance of the law, so that out of love he would fulfill its moral precepts. Thus, therefore, as long as someone is under the law in such a way that he does not fulfill the law voluntarily, sin has dominion in him, since the will of man is inclined to will that which is contrary to the law; but through grace such dominion is taken away, so that, namely, man keeps the law not as one existing under the law, but as one who is free. Galatians 4:31: "we are not the children of the bondwoman, but of the free: with which liberty Christ has made us free." But the sacraments of the law did not confer this grace which makes men freely fulfill the law; rather, the sacraments of Christ confer it. And therefore those who subjected themselves to the ceremonies of the law, as far as pertains to the power of those legal sacraments themselves, were not under grace, but under the law, unless perhaps they attained grace through faith in Christ. But those who subject themselves to the sacraments of Christ obtain grace from their power, so that they are not under the law, but under grace, unless perhaps through their own fault they subject themselves to the servitude of sin.

Then, when he says, "what then," etc., he raises a question against what has been said. And concerning this he does three things: first he sets forth the question; second he resolves it by leading to an absurdity, at the place, "God forbid. Know you not," etc.; third he shows that what he had led to is indeed absurd, at the place, "I thank God," etc.

Concerning the first it must be considered that the aforesaid statement could be wrongly understood by some, namely that the faithful of Christ are not under the law as regards the obligation of observing the moral precepts, from which it would follow that it would be lawful for the faithful of Christ to sin, that is, by acting against the moral precepts. And therefore in this sense he raises the question, saying: what then shall we say, shall we sin, namely by acting against the moral precepts of the law, since it has been said that we are not under the law, but under grace? And the Apostle disproves this sense in Galatians 5:13, saying: "you have been called unto liberty, my brothers; only make not liberty an occasion to the flesh." And therefore here too, in answering, he adds, "God forbid," namely that we should sin because we have been freed from the law; for if we were to sin, this absurdity would follow, that we would again be reduced to the servitude of sin.

And this is what he means when he says, "know you not, that to him to whom you present yourselves as servants, by your own will, to obey spontaneously, you are servants — to him whom you have obeyed." For to obey is a debt which servants owe to their masters. Ephesians 6:5: "servants, obey your masters according to the flesh." Hence when someone obeys another, by obeying he professes himself to be his servant. Yet different masters are obeyed for a different wage. For he who obeys sin is led, through the servitude of sin, unto death. And this is what he means when he says, "whether of sin," namely you are servants of it by obeying it. And this is "unto death," that is, unto being hurled headlong into eternal damnation, of which it is said in Revelation 2:11: "in these the second death has no place." But he who obeys God becomes the servant of this obedience; because through the habit of obeying, his mind is inclined more and more to obey, and from this he perfects justice. And this is what he means when he says, "or of obedience," namely of the divine precepts, you are servants unto the fulfilling of justice, according to that which was said above, 2:13: "the doers of the law shall be justified." And fittingly enough he opposes obedience to sin, because, as Ambrose says, sin is the transgression of the divine law and disobedience of the heavenly commandments.

Then, when he says, "but thanks be to God," he shows this to be absurd, namely that by obeying sin, we should again be brought back into the servitude of sin. First indeed by a reason taken from the benefit which we have obtained. For if someone is freed from servitude through another's favor, it is absurd that he should of his own accord subject himself again to servitude; hence, since we have been freed from sin through the grace of God, it is absurd that we should again of our own accord thrust ourselves back into the servitude of sin. Second, from the condition into which we have been led after liberty from sin, namely that we should be servants of justice. But it is not lawful for someone's servant to subject himself to the servitude of a contrary master; hence it is not lawful for us, since we have been made servants of justice, to return again to the servitude of sin.

The Apostle touches on both reasons at once, saying, "I give thanks to God" — thus you too ought to give thanks — that, whereas you were the servants of sin (because "he who commits sin is the servant of sin," John 8:34), you have obeyed, namely by believing, above 1:5: "unto obedience of the faith in all nations"; and this not under compulsion, but from the heart, below 10:10: "with the heart we believe unto justice"; unto that form of doctrine, that is, the doctrine of the Catholic faith, 2 Timothy 1:13: "holding the form of sound words which you have heard from me"; into which you have been delivered, 2 Corinthians 8:5: "they gave their own selves, first to God, then to us by the will of God." And through this you have been freed from sin, and so it is not fitting that you should abandon justice. 1 Corinthians 7:23: "you are bought with a price, and you are not your own."