The Epistle to Diogentus (10.7)

Then, though your lot be placed on earth you will see that God lives in heaven, then you will begin to speak of the mysteries of God, then you will both love and admire those who are being punished because they will not deny God, then you will condemn the deceit and error of the world, when you know what is the true life of heaven, when you despise the apparent death of this world, when you fear the death which is real, which is kept for those that shall be condemned to the everlasting fire, which shall punish up to the end those that were delivered to it.