Why is Christ's blood sacrifice necessary for salvation?

The necessity of Christ's blood is highlighted in Hebrews 9:6-7, where it states that the high priest could not enter the Most Holy Place without blood that was offered for himself and the people's sins. This emphasizes that without a suitable sacrifice, there is no access to God. Christ's sacrificial death fulfills what all previous sacrifices could only symbolize. Under the Old Covenant, sacrifices were ongoing but never sufficient for true forgiveness because they were merely shadows of the ultimate reality in Christ. His blood, poured out on the cross, fully satisfies the demands of God's holy justice for the sins of His people, as reiterated in Romans 3:25, where faith in His blood establishes Him as our propitiation.