Why is union with Christ significant for believers?

Union with Christ is a central theme in Reformed theology, emphasizing the believer's identity in relation to Christ. Scripture teaches that believers are united with Christ in His life, death, and resurrection (Romans 6:5). This union means that what Christ accomplished is imputed to the believer; as He was righteous, so too are they seen as righteous before God (2 Corinthians 5:21). Union with Christ assures believers that they are accepted by God, as they share in Christ's righteousness and stand justified in Him. This relationship transforms how believers live and relate to God, encouraging them to see themselves not as isolated individuals but rather as part of the body of Christ, unified in purpose and mission.