Currently Reading The Consequences of Ideas: Understanding the Concepts That Shaped Our World By R. C. Sproul see related

Our need for His Divine Grace...

"God created man with a free will, in which he also enjoyed perfect liberty.  Man had the faculty of choosing what he wanted.  He had the ability to sin (posse peccare) and the ability not to sin (posse non peccare).  He freely chose to sin out of his concupiscence (an inclination that leans to sin but is not sin).  As a result of the first sin, man lost his liberty but not his free will.  He was plunged, as a divine punishment, into a corrupt state known as original sin, losing the ability to incline himself to the things of God.  This resulted in man’s absolute dependence on a work of divine grace in his soul if he were ever to move toward God.  Fallen man is in bondage to sin.  He still has the faculty of choosing, a will free from coercion, but he now is free only to sin, because his desiers are inclined only toward sin and away from God.”  [Saint Augustine from Sproul's “The Consequences of Ideas”]