Why does growth usually hurt? Remember how when you were a kid, you'd have a growing spurt which were accompanied with pains or soreness in your legs? When our bodies grow they stretch, and stretching hurts. It's a fact of life.
Spiritual growth can hurt as well. There are trials of faith, growing spurts, which are accompanied with pain. However with spiritual growth, there is no medicinal pain reliever we can take. No, we must ride it out and pray that the Lord will ease the pain until we get through yet another trial of our faith.
The good news is that we do make it through, and come out stronger, taller, and more developed into the maturity of our faith. Then get ready for the next level of growth. When someone says pray the Lord to take you to a new level, I brace myself and pray, "According to thy will Lord. According to thy will." There is a cost for each new level, but the rewards are really worth it. Just trust Him to give the growth when He knows we can handle it. Selah!