What does it mean that Christ's redemption is secured?

Secured redemption implies that the work of Christ on the cross was sufficient and definitive for the salvation of those whom God has chosen. When Christ died for the ungodly, He bore their iniquities and fulfilled the law on their behalf (Romans 5:6-8). This transaction assures believers that their sins are paid for, and nothing can separate them from the love of God. The sealing of the Holy Spirit is a further guarantee, affirming that the elect are marked for redemption and will ultimately be adopted as God's children (Ephesians 1:13-14).