Augustine on Grace and Free Will
Catholics understand Grace as favour, the free and undeserved help that God gives us to respond to his call to become children of God, adoptive sons, partakers of the divine nature and of eternal life (Catechism of the Catholic Church # 1996). Grace depends entirely on God’s gratuitous initiative and demands man’s free response (ibid $ 1998, 2002). Without His Grace we cannot achieve our Justification. Quoting from Council of Trent’s declaration Catechism of the Catholic Church states (emphasis added):
The Synod furthermore declares, that in adults, the beginning of the said Justification is to be derived from the prevenient grace of God, through Jesus Christ, that is to say, from His vocation, whereby, without any merits existing on their parts, they are called; that so they, who by sins were alienated from God, may be disposed through His quickening and assisting grace, to convert themselves to their own justification, by freely assenting to and co-operating with that said grace: in such sort that, while God touches the heart of man by the illumination of the Holy Ghost, neither is man himself utterly without doing anything while he receives that inspiration, forasmuch as he is also able to reject it; yet is he not able, by his own free will, without the grace of God, to move himself unto justice in His sight.
Did the Catholic Church invent this teaching in sixteenth century AD to counteract Reformation? We look at some statement by Augustine regarding Grace and our Free will (English translation from Ancient Christian Commentary on Scripture, New Testament, Vol. VIII, page 258)
It is not in God’s power that anyone should be forced against his will to do evil or good but that he should go to the bad, according to his own deserts, when God abandons him. For a person is not good if he does not will it, but the grace of God assists him even in willing. It is not without cause that it is written, God is the one who works in you to will and do, of his own good will.
Augustine, On Two Letters of Pelagius 1.36
It is not that the will or the deed is not ours, but without his [God] aid we neither will nor do anything good.
Augustine, On the Grace of Christ 26
It is certain that when we do a deed, the deed, is ours; but he [God] is the one who makes us do the deed by giving us strength fully sufficient to carry out our will.
Augustine, On Grace and Free Will 32