After the fall man's will became severely damaged. Adam was the only man with a truly free will. His sin changed that free will. Luther referred to it as the bondage of the will.
Man maintaines a shadow of the original free will that God gave Adam..but man was made spiritually dead in the fall. His free will choices are limited by the effect of the fall. Man may still do exactly what he choices to do with his free will. But man will never chose God. He will choose between levels of evil..but he will never choose Christ without Gods grace.
When God regenerates the man, and gives him back the full free will that Adam lost man will be free to choose God once again.