How do we know that Christ's redemption is eternal?

In Revelation 13:8, Christ is referred to as the Lamb slain from the foundation of the world, highlighting that His redemptive work was essentially accomplished in God's plan even before creation. This teaching emphasizes that redemption is not merely a historical event but encompasses an eternal dimension. The sacrificial death of Christ on behalf of the elect assures believers that their sins are fully paid for, and thus their redemption is secure and unchangeable in the eyes of God.