A renewed heart comes from looking at what you can't see.

A renewed heart comes from something very strange: it comes from looking at what you can't see. "Look not at the things which are seen, but at the things which are not seen; for the things which are seen are temporal, but the things which are not seen are eternal." This is the way of not losing heart: looking at what you can't see.

Recall how Jesus criticized the religious leaders in his day: "Seeing they do not see and hearing they do not hear" (Matthew 13:13). In other words there was something to "see" in Jesus' life and His teaching which they didn't see but should have seen. That has got to be reversed if you are to get your hope and your courage from Jesus and not lose heart. It has to be said of you, "Not seeing, you see; and not hearing, you hear." You must be Looking at things that are not seen.

" Walk by faith, not by sight." This doesn't mean that you leap into the dark without evidence of what's there. But it does mean that the most precious and important realities in the world are beyond your senses, and you "look" at them through what you know of Christ from faithful witnesses who have seen him and heard his voice.  Strengthen your heart— renew your courage—by fixing the gaze of your heart on the invisible, real truth that you have learned through the testimony of those who knew Christ and were taught by him ( Ephesians 1:18–23).

Looking to the Unseen Weight of the Glory thats Being Prepared and Fix your gaze on Jesus day by day to renew your inner person in the face of death. Renew your inner person each day by looking at this truth: "Momentary, light affliction is producing for you an eternal weight of glory far beyond all comparison."

The decaying of your body is not meaningless. The pain, pressure, frustration, and affliction are not happening in vain. They are not vanishing into a black hole of pointless suffering. Instead this "momentary, light affliction [even though it lasted for years and was unremitting and often excruciating] is producing for you an eternal weight of glory far beyond all comparison."

In other words, the unseen things that Scripture speaks looks at renewing your inner person is the immense weight of glory that is being prepared for you not just after, but through and by, the wasting away of the flesh. There is a correlation between the decay of your body and the display of your glory. When you are hurting, fix your eyes not on how heavy the hurt is, but on how heavy the glory will be because of the hurt.

For know that if the earthly tent which is your house is torn down you have a building from God a house not made with hands. For indeed in this house you groan, longing to be clothed with your dwelling from heaven [that is, your resurrection body] Therefore, always being of good courage, and knowing that while you are at home in the body you are absent from the Lord. Full intimacy you long for is not here.