Augustine was a convert from Gnostic Manichaeism and kept some of the beliefs and introduced corrupted theology that was later picked up by Martin Luther and John Calvin. One of the most significant corruptions was the concept of original sin, the idea that we are born sinful and that our sin is not total and complete fault of our own.
http://www.gutenberg.org/files/3296/3296-h/3296-h.htm
http://www.newadvent.org/fathers/1101.htm
http://www.stoa.org/hippo/
http://www.newadvent.org/fathers/1201.htm
I used to have a friend who was a hero, a prophet, and a martyr in his own mind. I remember telling him he should start his own religion. A dig I suppose, because we both knew I wouldn't be one of the followers.
Back to Manichaeism - sounds complicated.
The concept pre-dated those two by a couple thousand years; Ps 51:5. Paul in Romans 5:12-14 discusses it as well.
I have been aware of the existence of the Manichean Heresy for at least 50 year, along with the Albigensian Heresy and the Arian Heresy. A few years ago I read a historic novel about the end of the Roman Empire in which Arianism figured prominently. I have forgotten the details and title of the book but basically it covers the rise and rule of a Gothic king/emperor who was an Arian and tried to save the Roman empire from its weak and dissolute leadership which suffered and cracked under the assaults of Attila the Hun and Alaric in the 500s AD. He was forced out of Italy (Ravenna?) and set up rule in what became France and had serious run-ins with Genseric, a Vandal who ruled in north Africa.
Arian Christianity was a much more tolerant form. It was tolerant of other brands of Christianity and was more friendly to women, among other things. The Roman church was successful in destroying Arianism, Manichaeism, and other offshoots of Christianity except for the Eastern Orthodox form. That whole period is very interesting.
Spot on and insightful. Most straying is for a ‘good’ cause.