Pelagius represents the moral theology, per Greenblatt, of original innocence: We’re all rational and morally competent creatures, and each of us can forge his or her own moral perfection through personal effort.This, it seems to me, flies in the face of experience, not only of the world, but of oneself. Original Sin is a theory I have yet see adequately falsified.
Augustine insisted that none of us are capable of achieving our own salvation; we need God’s grace to do that. God’s grace not only heals the wounds of sin—soothes us in our guilt and shame, and comforts us in our pain—but strengthens us against future temptations. We usually fail again, and are offered the same round of treatment and inoculation again. Thus the world around you is not filled with people who, if they cared to, could perfect themselves —a vision of profound pessimism— but with people who are doing, well, the best they can, and maybe it isn’t much, but it isn’t all there is, either. God loves us enough to help us along.