Christ says: When these things come to pass, look up, and lift up your heads, because your redemption is at hand. It is as if the Truth openly warns His Elect by saying: when the evils of this world mount up, when dread of the judgment is shown even by the trembling powers, lift up your heads, that is, be joyful in your hearts, because the world, of which you are not friends, is drawing to its end; the redemption you have been seeking is coming close. In Scripture the head is often used for the soul, because as the members are ruled by the head, so thoughts are governed by the soul. To lift up your heads therefore means to raise the heart to the joys of the heavenly fatherland.
They, therefore, who love God, are bidden to be glad, and to rejoice, because of the end of the world; since soon they will meet Him Whom they love, and that is passing away which they have never loved. Far be it then from any of the faithful who desire to see God that they should grieve over the stricken world, which we must know will end in these catastrophes. For it is written: Whosoever therefore will be a friend of this world, becometh an enemy of God (James 4:4). Who therefore does not rejoice at the approaching end of the world, testifies that he is its friend, and by this he is revealed as an enemy of God.
But let this be far from the faithful, far from the hearts of those who believe through their faith that there is another life, and who love it in very deed. Let them grieve over the ruin of the world who have planted the roots of their hearts deep in the love of it, who neither look for the life to come, nor are even aware that it is. But we who have learned of the joys of our heavenly home must hasten to it as speedily as we may. We should desire to go there with all haste, and to arrive by the shortest way. And with what miseries does not the world urge us forward? What sorrow, what misfortune is there, that does not press upon us? What is this mortal life but a way? And what folly would it be, let you carefully consider, to be weary with the fatigue of the way, and yet not eager to finish the journey!
St. Gregory the Great, Homily I, 12 November 590
Locus Communis 