Второ Коринтяни 4:15-18

All this is for your benefit, so that the grace that is reaching more and more people may cause thanksgiving to overflow to the glory of God.
Therefore we do not lose heart. Though outwardly we are wasting away, yet inwardly we are being renewed day by day. For our light and momentary troubles are achieving for us an eternal glory that far outweighs them all. So we fix our eyes not on what is seen, but on what is unseen, since what is seen is temporary, but what is unseen is eternal.