In Plantinga's third chapter of Engaging God's World, he addresses the fall in the Creation-Fall-Redemption sequence.
The first point that Plantinga makes that stood out to me was the fact that all philosophers, Christian or not, seem to look at evil as the root of any problem that man has faced. Even those thinkers that happen to reject God recognize that the world is out of joint and not nearly as good as it could be.
The next quote that really stuck out to me was, "If only there were evil people somewhere, insidiously committing evil deeds, and it were necessary only to separate them from the rest of us and destroy them. But the line dividing good and evil cuts through the heart of every human being. And who is willing to destroy a piece of his own heart?" This quote calls for a recognition of the totally depraved nature of all of our hearts and for the redemption of all things as it is not only a few individuals that spoil the world for the rest of us.