How does grace reign in a believer's life?

According to Romans 5:21, grace reigns through righteousness unto eternal life by Jesus Christ our Lord. This means that, in the life of a believer, grace not only forgives sin but also empowers to overcome sin. Unlike sin which leads to death, grace provides the means of living a righteous life, characterized by obedience to God and a transformed heart. Through the Holy Spirit, believers are given the strength to resist sin, cultivate righteousness, and pursue holiness, ultimately leading to eternal life.