How do we know that salvation is completely secure?

The security of salvation is rooted in the absolute and definite atonement provided by Christ. Romans 8:1 assures us that there is now no condemnation for those who are in Christ Jesus, affirming that once justified, believers are secure in their salvation. If salvation required further actions or contributions from individuals, it would not be based entirely on grace. Instead, Ephesians 2:8-9 emphasizes that we are saved by grace through faith, which is itself a gift from God, not a result of our own efforts.