7:14. For we know that the law is spiritual. But I am carnal, sold under sin.
7:15. For that which I work, I understand not. For I do not that good which I will: but the evil which I hate, that I do.
I do not that good which I will, etc… The apostle here describes the disorderly motions of passion and concupiscence; which oftentimes in us get the start of reason: and by means of which even good men suffer in the inferior appetite what their will abhors: and are much hindered in the accomplishment of the desires of their spirit and mind. But these evil motions, (though they are called the law of sin, because they come from original sin, and violently tempt and incline to sin,) as long as the will does not consent to them, are not sins, because they are not voluntary.
7:16. If then I do that which I will not, I consent to the law, that it is good.
7:17. Now then it is no more I that do it: but sin that dwelleth in me.
7:18. For I know that there dwelleth not in me, that is to say, in my flesh, that which is good. For to will is present with me: but to accomplish that which is good, I find not.
7:19. For the good which I will, I do not: but the evil which I will not, that I do.
7:20. Now if I do that which I will not, it is no more I that do it: but sin that dwelleth in me.
7:21. I find then a law, that when I have a will to do good, evil is present with me.
7:22. For I am delighted with the law of God, according to the inward man: