God does not act in us, says St. Augustine, as if we were lifeless stone or irrational creatures without free will. Because of our human freedom, we can resist that grace, we can turn away from the light, we can let the desires of the flesh and of the ego overshadow that light causing us to choose our will rather than God s . . . Yet, God so values human freedom that he will never take it away, even when man uses it to his own destruction. We do not mean that God cannot overcome our resistance if He so wills. For at times our human will is carried along by His grace in such a way that unfailingly we do what He wills, and yet we do it freely.
Theologians refer to such actual graces as efficacious graces.
When that actual grace is resisted or ignored, it is called sufficient grace. It was sufficient to dispose one to perform a meritorious act, but since that actual grace was resisted, that meritorious act did not follow. We can see from all this the importance of cooperating with God s grace, and of praying for the grace always to be open to God s action in the soul. When we say that every person that comes into this world receives sufficient grace for salvation, it is sufficient in the above sense. Each person is given sufficient interior divine lights and impulses to judge what is right and to do what is good, sufficient to bring him to the proximate disposition for action, i.e. to the point where action is immediately possible to us . . . awaiting only the cooperation of the will.