Pelagius on Will

From Pelagius's Defense Of The Freedom Of The Will, as quoted by Augustine:
"The man who hastens to the Lord, and desires to be directed by Him, that is, who makes his own will depend upon God's, who moreover cleaves so closely to the Lord as to become (as the apostle says) 'one spirit' with Him, does all this by nothing else than by his freedom of will."
"That we are able to do good is of God, but that we actually do it is of ourselves."
It seems to me that Pelagius has a valid interpretation. If we are not responsible for our own good behavior, it seems unjust for God to reward us for it. Heretics can still be right some of the time...