Eternal security, also known as "once saved, always saved", is the belief that from the moment anyone becomes a Christian, they will be saved from hell, and will not lose salvation. Eternal security is also known as "preservation of the saints", but should not be confused with the Calvinist doctrine of perseverance of the saints.
In Calvinism, eternal security is a logical consequence of the doctrine of perseverance of the saints, according to which true Christians will persevere in good works and faith. Because faith is God's perfect gift it will inevitably produce perseverance in faith and good works. Thus condemnation to hell because of sin, unbelief, or apostasy is not possible for true Christians.
In Catholicism, Christians do not have eternal security because they can commit a mortal sin. Catholics teach Christians are subject to the cleansing torment of purgatory before entrance into heaven.
Free grace theology says that anyone who believes in Jesus Christ will go to heaven regardless of any future actions – including future sin, unbelief, or apostasy – though Christians who sin or abandon the faith will face God's discipline.
- Pink, Arthur W. (2001). Eternal Security. Lafayette, IN: Sovereign Grace Publishers, Inc. pp. 39, 47, 58. ISBN 1589601955.
- Marshall, Taylor. "Can You Lose Your Salvation?". The Catholic Perspective on Paul. Retrieved 3 January 2019.
- Stanley, Charles (1990). Eternal Security: Can You Be Sure?. Nashville, TN: Thomas Nelson. pp. 81, 116–118. ISBN 0840790953.
- Shank, Robert (1989). Life in the Son. Minneapolis, MN: Bethany House Publishers. pp. 31–48. ISBN 1-55661-091-2.