The book of Job opens on a curious courtroom scene, where the satan, or the accuser, challenges God’s policy of rewarding righteous people like Job. He says that Job is only righteous because God has rewarded him. Let him suffer, he says, then we will see his true character.
The rest of the story is presented through dense Hebrew poetry, where Job, his wife, and his friends speculate on why Job is suffering. Isn’t he a righteous man? Why would God allow this? Job accuses God of being unjust and not operating the world according to principles of justice, and he calls on God to explain himself.
In response to Job’s plea, God takes him on a tour of the universe, reminding him that the world has order and beauty but it is also wild and dangerous. The problem of human suffering isn’t as simple as reward vs consequence. God’s world is much more complex than that, and he is holding aspects of the universe that we can’t even begin to comprehend. So while we do not always know why we suffer, we can bring our pain and grief to God and trust that he is wise and knows what he's doing.
The book of Job invites us to trust God’s wisdom and character no matter our circumstances.