How do we know Jesus Christ's sacrifice covers all time?

The understanding that Jesus Christ's sacrifice covers all time is rooted in the sovereignty of God and the eternal nature of Christ's atonement. As stated in the sermon, Christ's death occurred from eternity; this means that God's plan for redemption was decreed before the foundation of the world (Ephesians 1:4). Consequently, His atoning work is not confined to one moment in history. When Old Testament saints expressed their faith in God’s promises, they were simultaneously placing their faith in the coming Savior, who had already secured their redemption. Thus, the efficacy of Christ's sacrifice is timeless and applies to all God's elect across ages.