How do we know the doctrine of sin and grace is true?

The doctrine of sin and grace is firmly rooted in biblical teaching. 1 John 3:5 emphasizes that Jesus Christ was manifested to take away our sins, thereby highlighting the seriousness of sin and the necessity of grace. This passage assures believers that through faith in Christ, their sins are removed and they are reconciled to God. Furthermore, understanding our sinful nature and realizing the depth of God's grace motivates Christians to live righteously, as their transformation is evidence of grace at work within them.