In his book Trusting God, Jerry Bridges opens his chapter titled Growing through Adversity with the following illustration:
One of the many fascinating events in nature is the emergence of the Cecropia moth from its cocoon -- an event that occurs only with much struggle on the part of the moth to free itself. The story is frequently told of someone who watched a moth go through this struggle. In an effort to help -- and not realizing the necessity of the struggle -- the viewer snipped the shell of the cocoon.
Soon the moth came out with its wings all crimped and shriveled. But as the person watched, the wings remained weak. The moth, which in a few moments would have stretched those wings to fly, was now doomed to crawling out its brief life in frustration of ever being the beautiful creature God created it to be.
What the person in the story did not realize was that the struggle to emerge from the cocoon was an essential part of developing the muscle system of the moth's body and pushing the body fluids out into the wings to expand them. By unwisely seeking to cut short the moth's struggle, the watcher had actually crippled the moth and doomed its existence.
The adversities of life are much like the cocoon of the Cecropia moth. God uses them to develop the spiritual "muscle system" of our lives (see James 1:2-4).
So don't lose heart in your wearisome struggles; God is preparing you to fly.