On Grace and Free Will

Now if faith is simply of free will, and is not given by God, why do we pray for those who will not believe, that they may believe? This it would be absolutely useless to do, unless we believe, with perfect propriety, that Almighty God is able to turn to belief wills that are perverse and opposed to faith. Man's free will is addressed when it is said, “Today, if you will hear His voice, harden not your hearts.” But if God were not able to remove from the human heart even its obstinacy and hardness, He would not say, through the prophet, “I will take from them their heart of stone, and will give them a heart of flesh.” That all this was foretold in reference to the New Testament is shown clearly enough by the apostle when he says, “You are our epistle,... written not with ink, but with the Spirit of the living God; not in tables of stone, but in fleshly tables of the heart.” We must not, of course, suppose that such a phrase as this is used as if those might live in a fleshly way who ought to live spiritually; but inasmuch as a stone has no feeling, with which man's hard heart is compared, what was there left Him to compare man's intelligent heart with but the flesh, which possesses feeling? For this is what is said by the prophet Ezekiel: “I will give them another heart, and I will put a new spirit within you; and I will take the stony heart out of their flesh, and will give them a heart of flesh; that they may walk in my statutes, and keep mine ordinances, and do them: and they shall be my people, and I will be their God, says the Lord.” Now can we possibly, without extreme absurdity, maintain that there previously existed in any man the good merit of a good will, to entitle him to the removal of his stony heart, when all the while this very heart of stone signifies nothing else than a will of the hardest kind and such as is absolutely inflexible against God? For where a good will precedes, there is, of course, no longer a heart of stone.