Why does Christ's single offering on the Cross permanently supersede the repeated sacrifices of the Mosaic Law?

The author begins by contrasting the transitory shadows of the Mosaic Law with the enduring reality of Christ's redemption. Because the Old Covenant offered merely a silhouette of future spiritual goods rather than their true substance, its repetitive annual animal offerings were incapable of perfecting worshipers. Challoner clarifies that if those ancient rites had possessed intrinsic power to achieve complete forgiveness and reconciliation, their repetition would have ceased; instead, their yearly recurrence served as an enduring reminder of sin, since animal blood lacks the capacity to remove human guilt. Citing prophetic scripture, Christ is shown entering creation with the declaration that God took no delight in carnal oblations, but fashioned a human body for Him. By setting aside the preliminary sacrifices to accomplish the Father's sovereign will, the Son inaugurated the New Covenant, through which the faithful are sanctified once for all by the oblation of His physical body.

This definitive act supersedes the entire Levitical priesthood. While Aaronic ministers stand daily performing repetitive ceremonies that can never take away sins, Christ offered a solitary, unrepeatable sacrifice and sat down perpetually at the right hand of God, awaiting the ultimate defeat of His adversaries. By that single oblation, He has brought to everlasting perfection all who are sanctified. The Holy Spirit confirms this through the prophecy of the New Covenant, promising that divine laws will be inscribed directly upon human hearts and minds, and their past offenses remembered no longer. Challoner's gloss notes that where total remission of guilt is bestowed, as in baptism, no offering is needed for sins already remitted; subsequent sins can be remitted only by virtue of Christ’s one oblation.

Armed with this assurance, Christians possess unshakeable confidence to enter the heavenly sanctuary through the blood of Jesus, following the living path inaugurated through the veil of His flesh. Guided by this supreme High Priest over the household of God, believers are exhorted to draw near with sincere hearts in the full certitude of faith, purified within from a guilty conscience and cleansed externally in baptismal water. They must cling immovably to their public confession of hope, actively encouraging one another toward fraternal charity and noble works, while strictly avoiding the dangerous habit of neglecting communal worship as the day of divine judgment approaches.

The apostle follows this encouragement with a grave warning against apostasy, explaining that whoever deliberately repudiates known Christian truth faces the warning of no sacrifice left for sins. As Challoner explains, this warning targets deliberate defection from the faith, for which rebaptism cannot provide the ample remission of baptism again, and apostates seldom or never have grace to return. If someone who spurned the Mosaic law perished without pity upon the testimony of two or three witnesses, an incomparably heavier condemnation awaits anyone who treads underfoot the Son of God, treats as profane the covenant blood that sanctified him, and outrages the Holy Spirit of grace. Recalling that vengeance belongs to God, the author reminds the community that falling into the hands of the living God is a terrifying reality.

To sustain their perseverance, the author summons the Hebrews to remember their initial days after baptismal illumination, when they bravely endured public mockery, persecution, solidarity with chained captives, and the confiscation of their temporal goods, knowing they possessed a superior and imperishable heavenly inheritance. They must not cast aside this bold confidence, which carries an immense recompense, but embrace steadfast endurance so that after fulfilling God's will they may receive the promised prize. Prophecy assures them that the coming Lord will not delay; the righteous live by persevering faith, whereas God finds no pleasure in those who shrink back. The author concludes by affirming that believers do not belong to those who draw back into eternal ruin, but to those whose steadfast fidelity preserves the soul.