nature vs. nurture

In O'Connor's "The Artificial Nigger" there is a sense of society or the "worldly" (Mr. Head) and the ideal, innocent (Nelson). In this context the end, to me, was allegorical of Jesus. After the "artificial nigger" is broken and comes to the righteous and the unrighteous men, the unrighteous man (Mr.Head) realizes the error of his actions but also comes to the realization that it doesn't matter what sin's he has committed because he has been redeemed. At the same time Nelson has been so corrupted by the world, that he can no longer see things clearly and only takes fear from the experience. In reading this as an allegory, however, I wonder what O'Connor wants us to take away? Is it that Christ can redeem us all, or is it that there are no experiences that do not involve human weakness? Or maybe it is that faith comes to us not through our own doing, but by some benevolent gift from the almighty.