Why is eternal punishment fair?

Responding to the skeptic, there are number of possible answers to this question from the Christian perspective:

1.  There are many passages of Scripture, which seem to imply that those who enter Hell are eternally unrepentant. With this in mind, eternal punishment does seem fair. Dallas Willard has stated, “The fundamental fact about them will not be that they are there, but that they have become the kind of people so locked in their own self-worship and denial of God that they cannot want God.” Furthermore, it is possible that Hell will be an eternal lesson for the free beings in Heaven.

2.  We cannot forget that we are horribly guilty before God. (I fully explain this under Point 1 regarding why God ordered the killing of the Canaanites.)

3.  As a Christian, I believe God to be a perfect Judge who is fair in His pronouncements. (I fully explain this under Point 2 regarding why God ordered the killing of the Canaanites.)

4.  As a Christian, I believe we have inherited a corrupt nature from Adam, which is a direct consequence of rebellion against God. This nature pronounces are guilt, as it is a direct expression of our disobedience to our Creator. (I fully explain this under Point 2 regarding why we suffer for Adam’s sin.)