On Grace and Free Will

Why, therefore, do those very vain and perverse Pelagians say that the law is the grace of God by which we are helped not to sin? Do they not, by making such an allegation, unhappily and beyond all doubt contradict the great apostle? He, indeed, says, that by the law sin received strength against man; and that man, by the commandment, although it be holy, and just, and good, nevertheless dies, and that death works in him through that which is good, from which death there is no deliverance unless the Spirit quickens him, whom the letter had killed,— as he says in another passage, “The letter kills, but the Spirit gives life.” And yet these obstinate persons, blind to God's light, and deaf to His voice, maintain that the letter which kills gives life, and thus gainsay the quickening Spirit.

“Therefore, brethren” (that I may warn you with better effect in the words of the apostle himself), “we are debtors not to the flesh, to live after the flesh; for if you live after the flesh you shall die; but if you through the Spirit do mortify the deeds of the body, you shall live.” I have said this to deter your free will from evil, and to exhort it to good by apostolic words; but yet you must not therefore glory in man—that is to say, in your own selves,— and not in the Lord, when you live not after the flesh, but through the Spirit mortify the deeds of the flesh.

For in order that they to whom the apostle addressed this language might not exalt themselves, thinking that they were themselves able of their own spirit to do such good works as these, and not by the Spirit of God, after saying to them, “If you through the Spirit do mortify the deeds of the flesh, you shall live,” he at once added, “For as many as are led by the Spirit of God, they are the sons of God.” When, therefore, you by the Spirit mortify the deeds of the flesh, that you may have life, glorify Him, praise Him, give thanks to Him by whose Spirit you are so led as to be able to do such things as show you to be the children of God; “for as many as are led by the Spirit of God, they are the sons of God.”