14 How much more shall the blood of Christ, who through the eternal Spirit offered himself without spot to God, purge your conscience from dead works to serve the living God? It would seem that "the blood" here is used metaphorically for the sinless substitutionary sacrifice of the life of Christ ["offered himself without spot"] or the gospel truth that the righteousness of Christ (His sinless life) fully justifies believers. Thus satisfying and removing the condemning voice of conscience bringing internal peace based wholly upon Christ's sinless life imputed unto the sinner by faith. Otherwise, the condemnation by conscience would motivate the sinner to produce good works in hope of achieving justification for eternal life. However, such works are regarded as "dead" because no sinner can be justified in the sight of God by their own works but can only be further condemned unto death. Hence, the works do not obtain the goal which motivates them (life) but obtains death. The conscience is cleansed (katharsis) by the blood. Here "the blood" is used metaphorically for the gospel truth of Christ substitionary life of righteusness ("offered himself without spot") that removes the guilt produced by the condemnation of the conscience. Christ's substitutionary life and death is wholly sufficient to justify them before God thus cleansing the conscience from both condemnation and guilt. So when we sing "what can wash away my sin, nothing but the blood of Jesus" we are really saying the righteous life of Christ offered up in death satisfies the demands of the law for my justification before God. When someone prays "I claim the blood of Christ" over something or with regard to some promise of God, they are really saying "based upon the righteousness of Christ imputed to me" I come before the Father and claim these promises due to his righteousness not mine. "The blood" of Christ is used metaphorically in the Scriptures or to represent the gospel truth that sets us free based upon His righteousness.