It is astonishing that the apostle Paul says "light affliction" when in fact he endured very severe trials, the kind that few people can bear. He himself explains what this is about, saying that he sees his sufferings transformed. The apostle sees them already finished, sees what their fruit is - glory - and sees them from the point of view of eternity, the way God already now sees our suffering, when it hurts and seems it will never end. It will end and will be clothed with glory, as the Cross of Christ is completed by the Resurrection. And even now one can draw near to such vision if one looks "not at what is seen, but at what is unseen."
One can look at the unseen only by faith, which the apostle Paul defines as "conviction of things unseen" (Heb 11:1: "Faith is the substance of things hoped for and the conviction of things unseen"). Faith makes our sufferings fruitful, and everything of which our life consists. Only by faith, looking at the unseen, that is, keeping in our heart as the greatest treasure our trust in God - Creator, Provider, and Redeemer - do we become sighted, able to see the meaning of both our sufferings and our joys. Only by the path of faith can we rise to the height of the divine plan and the divine ways of economy, to the unshakable, firm support that is not subject to time, does not disappear, does not change, does not fail, because this support is God.