Augustine of Hippo

But perhaps Pelagius thinks that the name of Christ is necessary so that we may learn by his gospel how we ought to live, but not so that by his grace we may also be helped to lead good lives. At least, this consideration should lead him to admit that there are wretched shadows in the human soul, which knows how to tame a lion but not how to live. But are a free will and the natural law sufficient for us to know this? This is the "wisdom of speech" by which "the cross of Christ is made void." But he said, "I will destroy the wisdom of the wise," because that cross cannot be made void. And immediately is overthrown that "wisdom" through the "foolishness of preaching," by which those who believe are healed. For if the natural power through free will is sufficient for us not only to know how we ought to live but actually to live well, "then Christ died in vain," "then is the scandal of the cross made void." … Ignorant of the justice of God, you are seeking to establish your own justice, and you have not submitted to the justice of God. For even as Christ is the end of the law, so also is he the savior of corrupted human nature, to justice for all who believe.