"All men have sinned and are deprived of the glory of God. All men are now undeservedly justified by the gift of God, through the redemption wrought in Christ Jesus. Through his blood, God made him the means of expiation for all who believe. He did so to manifest his own justice." Rom 3:23-25
"This is the blood of the covenant, which will be shed on the behalf of many for the forgiveness of sins." Mt 26:28
Devotion to the Precious Blood became increasing popular in the 19th century due to a Roman priest named St. Gaspar del Bufalo. The Church sets aside the month of July as the calendar month particularly devoted to the Precious Blood. This devotion is connected to the Holy Name and the Most Sacred Heart of Jesus and was promoted by Pope John the XXIII. The Precious Blood of Christ, shed during the Passion, is the price He paid for our salvation. Since He shed His life's blood for us, it is only right that we live only for Him.