If you want to become stronger, you have to lift heavier things. I know this from CrossFit. The workouts aren't easy and people can't understand why I volunteer for such suffering, but I see tremendous improvement in all areas since I started. I'm stronger, faster, and have more endurance.
We often pray for patience or humility or something else along the lines of becoming better people. We want God to reach down and turn us into a better version of ourselves. He can, of course, do that, and does in many ways. Prayer, the sacraments, and other devotions are used to form us. But sometimes, we grow through suffering. When I have to fight myself to be patient with someone, I'm becoming a more patient person. It is a lot like lifting weights. Every time I suffer through something difficult, I become a better person. That doesn't sound awesome though. At CrossFit when I suffer, I can see the results immediately. I get a much hotter body and feel much better about myself. Generic suffering otherwise just seems so… painful. It is difficult to remember that suffering has a purpose and that God can (and does) use it for good in us.
Count it all joy, my brethren, when you meet various trials, for you know that the testing of your faith produces steadfastness. And let steadfastness have its full effect, that you may be perfect and complete, lacking in nothing. ~James 1:2-4
More than that, we rejoice in our sufferings, knowing that suffering produces endurance, and endurance produces character, and character produces hope, and hope does not disappoint us, because God’s love has been poured into our hearts through the Holy Spirit who has been given to us. ~Rom 5:3-5
This of course makes perfect sense as I write this blog, but nobody likes suffering and it is hard to keep it in mind when I'm suffering or when others are!