Why is it important for Christians to believe that God works within them?

For Christians, the belief that God works in them is essential for spiritual assurance and growth. According to Philippians 2:13, it is God who works in believers to will and to act according to His good purpose. This understanding enables Christians to recognize that their ability to serve God and live righteously is not derived from their efforts but from God's transformative work within them. This conviction fosters dependence on grace and encourages believers to pursue good works out of love for Christ.