Romans 7:11

"Sin" in this verse is to be understood as the devil, who is the author of sin. He found an opportunity through the law to satisfy his cruelty by the murder of man, so that as the law threatened sinners, man by instinct always did …

What does the Apostle mean when he writes to the Romans: "For sin, seizing the opportunity through the commandment, deceived me and through it killed me" (Rom 7:11)? Let us examine the whole passage and, with the help of Christ, try to understand its meaning. We do not wish to impose upon you our interpretation, but only to explain briefly what seems to us to be the true sense of the words. So what shall we say? Is the Law sin? Certainly not! Yet, I would not have known sin except through the Law.

Paul means by this that the fruit of a forbidden desire is sweeter. For this reason, sins committed in secret are sweeter, even if this sweetness is deadly.… It deceives us and turns into very great bitterness.

Paul means either that pleasure's persuasion to sin is more powerful when something is forbidden or else that, even if a man did do something in accordance with the law's requirements, if there is as yet no faith resting in grace, then he endeavors to attribute this to himself and not to God, and he sins all the more because of pride.

And even if, when the commandment comes — which is "holy and just and good" — sin revives in us and slays us ("for sin, taking occasion by the commandment, deceived me, and by it slew me"), it is no accusation of the commandment that he says the occasion by which sin slew me came from the commandment; but this is the logical consequence of that saying. That is called law which teaches what ought to be done and what avoided; and it is necessary that it should also teach of what sort that is which it says must be avoided, so that thereby it may the more easily be avoided. For no one can shun what he does not know. If, then, someone, having been taught by the law of what sort that is which he ought to avoid, does not so much avoid it as rather do it, he will indeed appear to have received, by occasion of the law, the knowledge of the thing that was not to be done: but the law had not taught him for this purpose, that he should do what he ought not, and die; but that he should not do it, and should live. Thus, then, "sin, taking occasion by the commandment, deceived me, and by it slew me." Or else, certainly, since he said, "Sin by the commandment deceived me, and by it slew me," he may here by "sin" have meant the very author of sin, of whom it is written, "The serpent deceived me"; or he may have fashioned a personification of sin, which is seen to have deceived the man by occasion of the commandment, so as to make concupiscence sweet, and that the soul, while it is delighted by the sweetness of concupiscence, might die by transgressing the commandment which said, "You shall not covet."