Compared with the holy rule of conduct in the law of God, the apostle found himself so very far short of perfection, that he seemed to be carnal; like a man who is sold against his will to a hated master, from whom he cannot set himself at liberty.
A real Christian unwillingly serves this hated master, yet cannot shake off the galling chain, till his powerful and gracious Friend above, rescues him. The remaining evil of his heart is a real and humbling hinderance to his serving God as angels do and the spirits of just made perfect.
This strong language was the result of St. Paul's great advance in holiness, and the depth of his self-abasement and hatred of sin. If we do not understand this language, it is because we are so far beneath him in holiness, knowledge of the spirituality of God's law, and the evil of our own hearts, and hatred of moral evil.
And many believers have adopted the apostle's language, showing that it is suitable to their deep feelings of abhorrence of sin, and self-abasement. The apostle enlarges on the conflict he daily maintained with the remainder of his original depravity.
He was frequently led into tempers, words, or actions, which he did not approve or allow in his renewed judgement and affections. By distinguishing his real self, his spiritual part, from the self, or flesh, in which sin dwelt, and by observing that the evil actions were done, not by him, but by sin dwelling in him, the apostle did not mean that men are not accountable for their sins, but he teaches the evil of their sins, by showing that they are all done against reason and conscience.
Sin dwelling in a man, does not prove its ruling, or having dominion over him. If a man dwells in a city, or in a country, still he may not rule there.