Mr. Augustine taught that humankind sinful by nature, and that without the grace of the Creator that sinfulness could only earn one eternal damnation. It is a totally negative view of humanity, which it goes contrary to my belief in the perfection God's creation. If God is perfect, then I sense so is the product of God's work.
According to Augustine, humankind's salvation came solely through the grace of God, as presented in the person and sacrifice of Jesus Christ, and that this grace came only by God's pleasure, to whomsoever he chose to extend it, without requiring any effort on man's part to complete the transaction.
Pelagius, a British monk, denied the doctrine of original sin, and by extension, the necessity for and the efficacy of Christ's sacrifice on the cross. He had a positive view of humanity and supported the idea that humanity is basically good.
In Pelagius' view, Augustine's doctrine seemed to teach that God only saves specific, chosen individuals, and those that aren't chosen, are, therefore, without hope, no matter how badly they want salvation. To him, this doctrine was cruel and exclusionary, since it appeared to him to be based solely on the whim of a capricious God.
Pelagius argued that individuals have free will. Augustine preached original sin (sinner at conception). Augustine believed that an individual will choose evil over good without the intervention of God (or the government which is empowered by God).
In the end, Augustine courted the Roman emperor Flavius Augustus Honorius (395-423 AD) and with a bribe of 80 Numidian stallions (via Augustine's friend and fellow bishop Alypius), swayed the emperor. In 418 Pope Zosimus excommunicated Pelagius, and Honorius condemned him as a heretic.
Through more than a little underhandedness on the part of Mr. Augustine, he managed to win out over his adversary. The result was that the more negative, sinful view of humankind won out. You have to ask yourself... "What if Augustine had played it straight? What if the guy's theology had lost out to a more Jesus-like teaching?"
Augustine, as bishop of Carthage: "...abandoned the policy of toleration practiced by the previous bishop of Carthage...[and] turned increasingly to force. First came laws denying civil rights to non-Catholic Christians; then the imposition of penalties, fines, eviction from public office; and finally, denial of free discussion... and the use of physical coercion." - Elaine Pagels
Augustine justified government and church subjugation of it's citizens based on his personal inability to choose good over evil and his assumption that everyone else must be as incapable as he. "After various earlier sexual relationships, he lived for years with a lower-class woman who engaged his passions and bore him a son, but then he abandoned her for the sake of a socially advantageous marriage his [christian] mother arranged for him." - Elaine Pagels
Augustine sold this view to Honorius by warning of the dangers of free will to the status quo... in Peter Browns' words: "the ultimate consequence of [Pelagian] ideas... cut at the roots of episcopal authority... The documents claimed that by appeasing the Palagians the Catholic church would lose the vast authority it had begun to wield..."Note: The most notable event of Honorius' reign was the assault and sack of Rome on August 24, 410 by the Visigoths under Alaric. The shock of this event reverberated from Britain to Jerusalem, and inspired Augustine to write his magnum opus, The City of God.