Nicene and Post-Nicene Fathers, Vol. II:
City of God: Chapter 28

Chapter 28.—The End of the Wicked.

But, on the other hand, they who do not belong to this city of God shall inherit eternal misery, which is also called the second death, because the soul shall then be separated from God its life, and therefore cannot be said to live, and the body shall be subjected to eternal pains.  And consequently this second death shall be the more severe, because no death shall terminate it.  But war being contrary to peace, as misery to happiness, and life to death, it is not without reason asked what kind of war can be found in the end of the wicked answering to the peace which is declared to be the end of the righteous?  The person who puts this question has only to observe what it is in war that is hurtful and destructive, and he shall see that it is nothing else than the mutual opposition and conflict of things.  And can he conceive a more grievous and bitter war than that in which the will is so opposed to passion, and passion to the will, that their hostility can never be terminated by the victory of either, and in which the violence of pain so conflicts with the nature of the body, that neither yields to the other?  For in this life, when this conflict has arisen, either pain conquers and death expels the feeling of it, or nature conquers and health expels the pain.  But in the world to come the pain continues that it may torment, and the nature endures that it may be sensible of it; and neither ceases to exist, lest punishment also should cease.  Now, as it is through the last judgment that men pass to these ends, the good to the supreme good, the evil to the supreme evil, I will treat of this judgment in the following book.