The elect are assured of eternal security because their salvation is based entirely on Christ's completed work, not on their own efforts.
The security of the elect in Christ is grounded in the doctrine of election and the sufficiency of Christ's atoning work. Ephesians 1:4-5 states that the elect were chosen in Christ before the foundation of the world, emphasizing God's sovereignty in salvation. Christ's work on the cross secured not only the forgiveness of sins but also the imputation of His righteousness to the elect, which guarantees their standing before God (2 Corinthians 5:21). The Holy Spirit serves as a seal of this promise, ensuring that all whom the Father has given to Christ will come to Him and will never be lost, as expressed in John 6:39-40.
Scripture References:
Ephesians 1:4-5, 2 Corinthians 5:21, John 6:39-40
Commentary