When will a man guilty of any crime or sin accept with a tranquil mind that his wickedness is a product of his own will, not of necessity, and allow … - Pelagius

It was because God wished to bestow on the rational creature the gift of doing good of his own free will and the capacity to exercise free choice, by implanting in man the possibility of choosing either alternative. ... He could not claim to possess the good of his own volition, unless he was the kind of creature that could also have possessed evil. Our most excellent creator wished us to be able to do either but actually to do only one, that is, good, which he also commanded, giving us the capacity to do evil only so that we might do His will by exercising our own. That being so, this very capacity to do evil is also good – good, I say, because it makes the good part better by making it voluntary and independent, not bound by necessity but free to decide for itself.

If you depart from evil but fail to do good, you transgress the law, which is fulfilled not simply by abominating evil deeds but also by performing good works.

Whenever I have to speak on the subject of moral instruction and the conduct of a holy life, it is my practice first to demonstrate the power and quality of human nature.