Why does God allow sickness?

TL;DR:

Sickness exists because we live in a fallen world, but God uses even sickness for our good and His glory. Even when we don’t understand why God allows sickness, we can trust that He is sovereign, good, and with us in our suffering.

what does the bible say?

Sickness can be a challenging topic. We think that a good and loving God would not allow sickness, and yet we know that sickness exists. We can begin to believe that sickness is the result of a person's sin. While that may sometimes be the case, sickness is often just a result of living in a fallen world. Sickness can test and refine our faith or display God’s glory. Sickness may also be a form of discipline or even a spiritual attack, but it always falls under God’s sovereign control. While we may not understand the reasons God allows suffering, we can trust that God works through sickness for our good and His glory. We can also trust that He is with us. In all suffering, God remains present, compassionate, and faithful to His people.

from the old testament

Sometimes, sickness is just a natural result of living in a world marred by sin (Genesis 3:16–19).
Sickness could be used to test and refine our faith, as Job's trials were (Job 1:6–12; 2:3–7).
Sickness could also be a form of discipline, a tangible demonstration of an imperfect life that leads us to greater dependence on and obedience to God (Psalm 119:65–72).
Even though sickness is a reality of life, it is also true that God uses all things, including sickness, for good and is with us through our difficulty (Genesis 50:20; Deuteronomy 31:6, 8; Psalm 34:18–19; Isaiah 41:10).
An important thing to remember is that God's ways are not our ways (Isaiah 55:8–9).
Just as Job did not know the reasons he was suffering, God may not reveal to us the full purpose behind our sickness or trials. Yet we can trust that He is sovereign, wise, and working all things for His glory and our ultimate good.

from the new testament

Sickness is a natural result of living in a world deeply impacted by sin (Romans 8:20–22).
At times, sickness can also be an attack of Satan (Matthew 17:14–18; Luke 13:10–16).
John 9 describes Jesus healing a man who had been blind since birth. Jesus' disciples asked if the man's blindness was caused by his sin or that of his parents. Jesus replied, "Neither this man nor his parents sinned…but this happened so that the works of God might be displayed in him" (John 9:3 [NIV]). In this case, God allowed sickness in order that His glory might be shown.
If we trust in the sovereignty and the goodness of God, we know that nothing happens outside of His will (Matthew 10:29; Ephesians 1:11; see Job 42:2), and we also know that everything He does is motivated by love (1 John 4:8; Luke 18:19). Therefore, sickness must fit into His will and into His loving nature. This is not to say that God is the cause of sickness.
Often, we do not understand exactly why God allows things to happen or causes things to happen a certain way. But we do know God and can trust in His character. He is for us (Romans 8:31–32).
Even in sickness, we "know that for those who love God all things work together for good, for those who are called according to his purpose. For those whom he foreknew he also predestined to be conformed to the image of his Son, in order that he might be the firstborn among many brothers" (Romans 8:28–29). Even in a sickness we may not understand, we can trust that in God's timing, the sickness will be redeemed. God will work it into His good purpose for our lives and for His glory.
God is also with us through our difficulties, including sickness (Matthew 28:20; John 16:33; Romans 8:28; 2 Corinthians 12:9–10; Hebrews 13:5).

implications for today

The truth that God is good and sovereign and uses all things, including sickness, for good is often not particularly comforting to someone in the grips of an illness. Yes, God knows His purpose in the sickness and that things will turn out for our good and His glory, but that purpose is not always evident to us. We legitimately go through times of questioning God and feelings of pain. God is not offended when we pour out our hearts to Him. We are allowed to approach God with our sicknesses, to request healing, and to share our hurt with Him. Look at the Psalms! We can be viscerally honest with God while still trusting in His goodness and faithfulness. God is not hardened to our emotions (John 11:35; Psalm 56:8); He cares for us and invites us to give our struggles over to Him (1 Peter 5:7).

understand

Sickness is a result of living in a fallen world.
God uses even sickness for our good and His glory.
God is with us in our suffering.

reflect

How do you respond emotionally and spiritually when sickness touches your life or the life of someone you love?
How can you trust God’s sovereignty even when you don’t understand the purpose of suffering?
How might you allow sickness to refine your faith and draw you closer to God?

engage

How have you seen God use sickness or trials to display His glory in someone’s life?
How do we balance the reality of a fallen world with the promise that God works all things for good?
In what practical ways can we support those who are suffering?