What does the Bible say about the significance of blood in the altar?

In Leviticus 4, the sprinkling of blood before the altar signifies the gravity of sin and the necessity of atonement through suffering and death. Blood represents the life that is taken and the severe consequence of sin against God. God's justice demands that sin be punished, and the only way for this demand to be met is through a perfect sacrifice. This foreshadowing ultimately points to the blood of Christ, which cleanses from all sin as He was the fulfillment of every sacrifice that was ever offered.