Augustine on Free Grace
The human will is so divinely helped in the pursuit of righteousness, that he [the believer] receives the Holy Spirit, by whom there is formed in his mind a delight in, and a love of, that supreme and unchangeable good, which is God. By this gift to him of the down payment, as it were, of the free gift, he [the believer] conceives a burning desire to cleave to his Maker. A mans free will, indeed, does not help at all except to sin, if he does not know the way of truth. And even after he begins to know his duty and proper aim, unless he also takes delight in and feels a love for it, he neither does his duty, nor sets about it, nor lives rightly. Now, in order that such a course may engage our affections, Gods love is shed abroad in our hearts, not through the free will which arises from ourselves, but through the Holy Spirit, who is given to us [Rom 5: 5].
~Augustine~
What is grace? That which is freely given. What is “freely given”? Given, not paid. If it was due, wages would be given, but grace would not be bestowed. But if it was really due, then you were good. But if, as is true, you were evil but believed on him who justifies the ungodly (What is, “who justifies the ungodly”? the ungodly is made righteous), consider what by right hung over you by the law and you have obtained by grace. But having obtained that grace by faith, you will be just by faith—”for the just lives by faith.”
~Augustine~
"In some places God requires newness of heart [Ezek 18:31]. But elsewherre he testifies that it is given by him [Ezek. 11:19; 36:26]. But what God promises we ourselves do not do through choice or nature; but he himself does through grace."-