Christ's blood cleanses from sin because it was the righteous sacrifice that paid the penalty for our sins.
The cleansing power of Christ's blood is foundational to the doctrine of redemption. The Apostle Paul states in Romans 3:24-25 that we are justified freely by His grace through the redemption that is in Christ Jesus, whom God set forth to be a propitiation through faith in His blood. The blood of Christ represents not only His suffering but also His righteousness as the sinless Lamb of God. This blood cleanses the believer from all sin, enabling them to stand justified before God, thus emphasizing the core teaching of the New Testament that without the shedding of blood, there is no remission of sins (Hebrews 9:22).
Scripture References:
Romans 3:24-25, Hebrews 9:22, 1 Peter 1:18-19
Commentary