Knowing God is in control and that he loves us should lead us to look for his loving hand even in our suffering. If you are facing difficulty right now, as a Christian, you may not fully understand what God is doing, but during it, you can look for the work of grace in your heart. No one seemed to understand this better than the Puritans. Below are four spiritual advantages of affliction, as summarized by Thomas Watson.
1. Affliction shows us more of our own hearts.
Water in a glass looks clear but set it on the fire, and the scum boils up! Just so, when God sets us upon the fire, corruption boils up, which we did not discern before.
Sharp afflictions are to the soul as a soaking rain to the house; we do not know that there are holes in the roof until the shower comes, but then we see it drop down here and there. Just so, we do not know what unmortified lusts are in the soul, until the storm of affliction comes, then the hidden evils of the heart come dropping down in many places. Affliction is a sacred eye salve—it clears our eyesight. Thus, the rod gives wisdom.
2. Affliction quickens the spirit of prayer.
Jonah was asleep in the ship but at prayer in the whale’s belly! Perhaps in a time of health and prosperity, we prayed in a cold and formal manner; we put no fire to the incense. Then God sends some affliction or other to stir us up to take hold of Him. “They poured out a prayer when Your chastening was upon them” (Isaiah 26:16). In times of trouble, we pray feelingly and fervently.
3. Affliction is a means to purge out our sins.
Affliction cures the pestilence of pride and the fever of lust. Affliction is God’s file to scrub off our rust. Affliction is God’s flail to thresh off our husks. The water of affliction is not to drown us but to wash off our spots.
4. Affliction is a means to wean us from the world.
The world often proves not only a spider’s web but a dragon’s egg. Corrupting worldly things are great enchantments. They hinder us in our passage to heaven. Affliction sounds a retreat, to call us off the immoderate pursuit of earthly things. When two things are frozen together, the best way to separate them is by fire; so, when the heart and the world are together—God has no better way to separate them than by the fire of affliction.
-Thomas Watson
The Fight of Faith 