Those whom God saves are saved forever. Those whom God saves He empowers to endure in the faith until the end (Mk 13:13). This is the doctrine known as the perseverance of the saints. Sometimes referred to as the security of the believer, this doctrine exalts the keeping power of God in salvation. That is, it rests on the foundation of Paul’s triumphant declaration in Romans 8:29-30, “For whom He foreknew, He also predestined to become conformed to the image of His Son, that He might be the first-born among many brethren; and whom He predestined, these He also called; and whom He called, these He also justified; and whom He justified, these He also glorified.” Simply stated, of all those whom God saves, not one shall be lost. Steele, Thomas, and Quinn write,
The doctrine of the perseverance of the saints does not maintain that all who profess the Christian faith are certain of heaven. It is saints—those who are set apart by the Spirit—who persevere to the end. It is believers—those who are given true, living faith in Christ—who are secure and safe in Him. Many who profess to believe fall away, but they do not fall from grace, for they were never in grace. True believers do fall into temptations, and they do commit grievous sins, but these sins do not cause them to lose their salvation or separate them from Christ.
The assurance of our salvation is not based on our self-empowered efforts to “keep ourselves saved,” but rather on the fact that, from beginning to end, salvation is a work of God’s sovereign grace. Though we may stumble and fall along the way we are able to live the obedient Christian life in the strength of the Spirit, being “confident of this very thing, that He who began a good work in [us] will perfect it until the day of Christ Jesus” (Philippians 1:6). All glory and praise to the Lamb upon His throne!