What happens to those who are in Christ according to the Bible?

According to Romans 5:18-19, the righteousness of Christ brings justification to many, contrasting the condemnation that came through Adam's sin. When a person is united with Christ by faith, they experience a transformation; they are made alive spiritually and declared righteous, possessing a new identity as children of God. This concept of ‘being in Christ’ reflects the believers’ participation in Christ’s life, death, and resurrection, ensuring their security and hope for eternal life.