Why is understanding the doctrine of sin important for Christians?

The doctrine of sin, as delineated in scripture, reveals that all have sinned and fall short of the glory of God (Romans 3:23). This understanding acknowledges that our sin originates from within our hearts, leading to actions that are contrary to God's holiness. Recognizing our sinful nature highlights the necessity of Jesus Christ's sacrifice, as only His blood can cleanse us from all unrighteousness. This awareness compels believers to rely on grace and not on their works, reinforcing that salvation is through faith alone in Christ alone.