From Hope When You're Hurting by Crabb and Allender:

"So what is our hope? Simply this: That nothing, no problem in our circumstances or in our souls, can keep us from living out God's purpose for our lives if we are abandoned to him. If cancer blocks that purpose, it will be removed. If depression gets in the way, it will lift. If fatigue from poor sleep keeps us from fulfilling God's agenda, we'll snore with the best of them. If wealth is part of the plan, we'll close the big deal.

But, when illness, discouragement, prodigal children, insomnia, and money struggles are useful to God in advancing his purposes, they will be a part of our lives. We are not wrong to take whatever honorable measures we can to alleviate our suffering, and we are not wrong to thank God if things improve. But, because we cannot always understand what God is up to, we are wrong to demand less suffering, to make it our top priority to change things to be the way we would like."