Read Transformed by Trials, by DR Tony Evans at One Place
"One of the primary ways God makes us more like Christ is by allowing us to face trouble. To conform us into the image of Christ, we don’t just need minor surgery--we require major transformation. In fact, God has to put a brand new nature inside us. Just as a sculptor chips away at a piece of marble to turn it into a beautiful sculpture, God uses trials to chip away at us, sculpting us to resemble the image of Christ."
Consider it all joy, my brethren, when you encounter various trials... (James 1:2)