18 Nor let anybody think that Christians are not avenged by those things that are happening, for the reason that they also themselves seem to be affected by their visitation. A man feels the punishment of worldly adversity, when all his joy and glory are in the world. He grieves and groans if it is ill with him in this life, with whom it cannot be well after this life, all the fruit of whose life is received here, all whose consolation is ended here, whose fading and brief life here reckons some sweetness and pleasure, but when it has departed hence, there remains for him only punishment added to sorrow. But they have no suffering from the assault of present evils who have confidence in future good things. In fact, we are never prostrated by adversity, nor are we broken down, nor do we grieve or murmur in any external misfortune or weakness of body: living by the Spirit rather than by the flesh, we overcome bodily weakness by mental strength. By those very things which torment and weary us, we know and trust that we are proved and strengthened.
Source: The Treatises of Cyprian (New Advent)