The same view is to be taken of the expression which next follows, -- that he did not the good which he desired, but, on the contrary, the evil which he desired not: for the faithful, however rightly they may be influenced, are yet so conscious of their own infirmity, that they can deem no work proceeding from them as blameless. For as Paul does not here treat of some of the faults of the godly, but delineates in general the whole course of their life, we conclude that their best works are always stained with some blots of sin, so that no reward can be hoped, unless God pardons them. He at last repeats the sentiment, -- that, as far as he was endued with celestial light, he was a true witness and subscriber to the righteousness of the law. It hence follows, that had the pure integrity of our nature remained, the law would not have brought death on us, and that it is not adverse to the man who is endued with a sound and right mind and abhors sin. But to restore health is the work of our heavenly Physician.

For the good - This is substantially a repetition of what is said in Romans 7:15. The repetition shows how full the mind of the apostle was of the subject; and how much inclined he was to dwell upon it, and to place it in every variety of form. It is not uncommon for Paul thus to express his intense interest in a subject, by placing it in a great variety of aspects, even at the hazard of much repetition.

For the good that I would I do not - Here again is the most decisive proof that the will is on the side of God and truth.
But the evil which I would not - And here is equally decisive proof that the will is against, or opposed to evil. There is not a man in ten millions, who will carefully watch the operations of this faculty, that will find it opposed to good and obstinately attached to evil, as is generally supposed. Nay, it is found almost uniformly on God's side, while the whole sensual system is against him. - It is not the Will that leads men astray; but the corrupt Passions which oppose and oppress the will. It is truly astonishing into what endless mistakes men have fallen on this point, and what systems of divinity have been built on these mistakes. The will, this almost only friend to God in the human soul, has been slandered as God's worst enemy, and even by those who had the seventh chapter to the Romans before their eyes! Nay, it has been considered so fell a foe to God and goodness that it is bound in the adamantine chains of a dire necessity to do evil only; and the doctrine of will (absurdly called free will, as if will did not essentially imply what is free) has been considered one of the most destructive heresies. Let such persons put themselves to school to their Bibles and to common sense.
The plain state of the case is this: the soul is so completely fallen, that it has no power to do good till it receive that power from on high. But it has power to see good, to distinguish between that and evil; to acknowledge the excellence of this good, and to will it, from a conviction of that excellence; but farther it cannot go. Yet, in various cases, it is solicited and consents to sin; and because it is will, that is, because it is a free principle, it must necessarily possess this power; and although it can do no good unless it receive grace from God, yet it is impossible to force it to sin. Even Satan himself cannot do this; and before he can get it to sin, he must gain its consent. Thus God in his endless mercy has endued this faculty with a power in which, humanly speaking, resides the salvability of the soul; and without this the soul must have eternally continued under the power of sin, or been saved as an inert, absolutely passive machine; which supposition would go as nearly to prove that it was as incapable of vice as it were of virtue.
"But does not this arguing destroy the doctrine of free grace?" No! it establishes that doctrine.
1. It is through the grace, the unmerited kindness, of God, that the soul has such a faculty, and that it has not been extinguished by sin.
2. This will, though a free principle, as it respects its nilling of evil and choosing good, yet, properly speaking, has no power by which it can subjugate the evil or perform the good.
We know that the eye has a power to discern objects, but without light this power is perfectly useless, and no object can be discerned by it. So, of the person represented here by the apostle, it is said, To will is present with me, το γαρ θελειν παρακειται μοι. To will is ever in readiness, it is ever at hand, it lies constantly before me; but how to perform that which is good, I find not; that is, the man is unregenerate, and he is seeking justification and holiness from the law. The law was never designed to give these - it gives the knowledge, not the cure of sin; therefore, though he nills evil and wills good, yet he can neither conquer the one nor perform the other till he receives the grace of Christ, till he seeks and finds redemption in his blood.
Here, then, the free agency of man is preserved, without which he could not be in a salvable state; and the honor of the grace of Christ is maintained, without which there can be no actual salvation. There is a good sentiment on this subject in the following words of an eminent poet: -
Thou great first Cause, least understood;
Who all my sense confined
To know but this, that thou art good;
And that myself am blind.
Yet gave me in this dark estate
To see the good from ill;
And binding nature fast in fate,
Left free the human will.
Pope's Universal Prayer.

For the good that I would, I do not,.... The apostle here repeats what he had delivered in Romans 7:15 to strengthen and confirm this part of his experience; that though he had a will to that which was good, yet he wanted power, and had none of himself to perform; and therefore often did what he would not, and what he would he did not.

For, &c.--The conflict here graphically described between a self that "desires" to do good and a self that in spite of this does evil, cannot be the struggles between conscience and passion in the unregenerate, because the description given of this "desire to do good" in Romans 7:22 is such as cannot be ascribed, with the least show of truth, to any but the renewed.