What does the Bible say about sorrow turning to joy?

In John 16:20, Jesus tells His disciples that they will weep and lament while the world rejoices, but their sorrow will be turned into joy. This promise reflects the profound transformation that occurs through Christ's suffering, death, and resurrection. When believers understand the purpose of Christ's sacrifice, recognizing that it brings about their redemption, the sorrow initially experienced gives way to deep, abiding joy. This joy is not based on earthly circumstances but on the eternal assurance of salvation and righteousness through Christ's work.