Hello, is it OK if I make a comment about this topic?
In my opinion and according to my knowledge, Pelagius didn't teach that man could be sinless without God.
"I did indeed say that a man can be without sin and keep the commandments of God, if he wishes, for this ability has been given to him by God. However, I did not say that any man can be found who has never sinned from his infancy up to his old age, but that, having been converted from his sins, he can be without sin by his own efforts and God's grace, yet not even by this means is he incapable of change for the future." - His answer at the synod of Diospolis.
His ideas were rejected not only on theological but on political grounds too, because he basically rejected(me too) nominal Christians, who continued to live sinful life that they previously had...
Why was his doctrine so eagerly criticized? Didn't early Church Fathers teach the same about moral perfection? Pelagius didn't deny the grace of God, he just emphasized the ability of man to be sinless according to his will, which would obviously be helped by God, why would God desert a man with such enthusiasm? If we fully follow Augustine's idea, that means - men are evil, only God chooses who can follow his commandments - that's just blasphemy - ignoring God's justice...
So, does church anathemize the idea, that Christian should be sinless or that he can be if he wants to?
Augustine's famous refutation is: "It is impossible not to sin" - means even all Church Fathers were continuously sinning after starting holy life...
He rejected original sin, but was that original idea of Church? That human nature was tainted? Can't unbeliever live purely Christian life?