What does the Bible mean by 'the blood of Jesus cleanses us from all sin'?

The phrase 'the blood of Jesus cleanses us from all sin' found in 1 John 1:7 encapsulates the core of Christian salvation. This cleansing refers to the atoning sacrifice of Christ, where His blood was shed to pay the penalty for sin. By faith, believers are united with Christ, and His righteousness is imputed to them. This demonstrates that while we are sinners by nature, God's provision through Christ’s blood offers total forgiveness and purity. Thus, the act of believing in Christ is the means by which we receive this cleansing, highlighting the importance of His sacrificial death in our redemption and ongoing sanctification.