The first document of the semi-Pelagian controversy, the Defense of St. Augustine examines several mutually connected points of doctrine, all of them centered on the gratuity of grace, the undeserved gift of God.
“The just man liveth by faith.42 And: Without faith no one can please God.43 And: All that is not of faith is sin.44 So, he should understand that the justice of infidels is no justice,45 because nature without grace is unclean.” (Page 27)
“But let such absurd and baneful opinion be far from the minds of Christians redeemed by the blood of the Christ! Human nature cannot be made free apart from the one Mediator of God and men, the man Christ Jesus:68 without Him there is no salvation.69 Just as He made us and not we ourselves,70 so also He remakes us and not we ourselves.” (Page 30)
“By the sin of Adam all men lost their natural ability for good and their innocence.8 No one can rise from the depths of this fall of his own free will unless he be raised by the grace of God’s mercy.” (Page 179)