2 Corinthians 4:16
“Wherefore we faint not; but though our outward man is decaying, yet the inward man is renewed day by day.”
How does it decay? Being scourged, being persecuted, suffering ten thousand extremities. “Yet the inward man is renewed day by day.” How is it renewed? By faith, by hope, by a forward will, finally, by braving those extremities. For in proportion as the body suffers ten thousand things, in the like proportion has the soul goodlier hopes and becomes brighter, like gold refined in the fire more and more. And see how he brings to nothing the sorrows of this present life.
Source: Homilies on Second Corinthians (New Advent)