Eternal Security, often associated with the doctrine of "once saved, always saved," is a theological belief in Christianity that asserts once a person has genuinely accepted Jesus Christ as their Savior, they cannot lose their salvation. This concept is rooted in various biblical passages that emphasize God's grace and the permanence of His promises. Proponents of Eternal Security argue that salvation is a gift from God that cannot be revoked, regardless of a believer's future actions or sins. Critics, however, contend that this belief may lead to complacency in faith and moral behavior, raising questions about the nature of true belief and repentance.