The problem of evil is often stated: If God is all-powerful, all-knowing, and all-good, why does evil exist? An all-powerful God could prevent evil. An all-knowing God would know about evil. An all-good God would want to prevent evil. Yet evil exists.
Christianity has developed several responses:
The Free Will Defense (Alvin Plantinga): God created beings with genuine free will because love and virtue require the possibility of choice. A world of free agents inevitably includes the possibility of moral evil. God could not create genuinely free beings who were guaranteed to always choose good.
The Soul-Making Theodicy (John Hick): Suffering plays a role in the development of character, virtue, and spiritual maturity. A world without challenges would not produce courageous, compassionate, or resilient human beings.
The Greater Good Argument: God may permit particular instances of evil because they are necessary conditions for greater goods. Joseph told his brothers: 'You meant it for evil, but God meant it for good' (Genesis 50:20).
The Cross as God's Answer: Christianity does not claim that God is distant from suffering. The cross demonstrates that God entered into human suffering, experienced it fully, and redeemed it from within. 'Surely he hath borne our griefs, and carried our sorrows' (Isaiah 53:4).
The Eschatological Hope: Christianity promises ultimate justice and restoration. Every wrong will be made right. Every tear will be wiped away (Revelation 21:4).
Importantly, the existence of evil is also a problem for atheism. If there is no God, there is no objective standard by which anything can be called truly 'evil.'