The blood of Christ
Life had to be forfeited for our sins, and no life is more precious than that of God who became man. His blood was the blood of the God-man, and therefore he paid the infinite price. We were not bought with gold and silver, but with the precious blood of Christ. That is how our sins are forgiven, and that is why our Blessed Lord prayed for our forgiveness at the moment that he poured out his blood for us sinners. If you have faith in Jesus' sacrifice, now is the time to go to confession, to get rid of your sins. When the priest raises his hands in absolution over you, the blood of Christ is dripping from his fingers. We priests are hardly conscious of this great power. I think we would almost be shocked to death if we ever really realized it. But that is how the sin is absolved, by this blood of Christ.