Romans 7:17

But if according to our will we consent to the law of God, then the evil which we do, it is no longer we who work it, but the sin which is in us — that is, the law and the will of the flesh, which leads us captive in the law of sin which is in our members. And here indeed the carnal Paul says, "It is no longer I who work it, but the sin that dwells in me." But the spiritual Paul says elsewhere, "I labored more abundantly than all of them; yet not I, but the grace of God with me." Therefore, just as this one ascribes his labors not to himself, but to the grace of God which was working in him, so also that carnal one reckons his works, which are not good, not to himself, but to the sin which dwells and works in him. For this reason therefore he says: "It is no longer I who work it, but the sin that dwells in me."

All this is reminiscent of what was said by the Lord in the Gospels: "The spirit is willing but the flesh is weak."

On this text, those who find fault with the flesh, and contend it was no part of God's creation, attack us. What are we to say then? Just what we did before, when discussing the Law: that as there he makes sin answerable for everything so here also. For he does not say, that the flesh worketh it, but just the contrary, "it is not I that do it, but sin that dwelleth in me." But if he does say that "there dwelleth no good thing in it," still this is no charge against the flesh. For the fact that "no good thing dwelleth in it," does not show that it is evil itself. Now we admit, that the flesh is not so great as the soul, and is inferior to it, yet not contrary, or opposed to it, or evil; but that it is beneath the soul, as a harp beneath a harper, and as a ship under the pilot. And these are not contrary to those who guide and use them, but go with them entirely, yet are not of the same honor with the artist. As then a person who says, that the art resides not in the harp or the ship, but in the pilot or harper, is not finding fault with the instruments, but pointing out the great difference between them and the artist; so Paul in saying, that "in my flesh dwelleth no good thing," is not finding fault with the body, but pointing out the soul's superiority. For this it is that has the whole duty of pilotage put into its hands, and that of playing. And this Paul here points out, giving the governing power to the soul, and after dividing man into these two things, the soul and the body, he says, that the flesh has less of reason, and is destitute of discretion, and ranks among things to be led, not among things that lead. But the soul has more wisdom, and can see what is to be done and what not, yet is not equal to pulling in the horse as it wishes. […]

"When I say 'me,'" he says, "understand that which is more excellent in me, in which I also stand by the grace of God, that is, the mind and reason. When I speak of 'my soul,' take it in the lower sense, that which you …

He did not say that the flesh does this, but "sin," that is, the tyranny of sin that drags me along.