The teaching of ‘once saved always saved’ (sometimes abbreviated ‘OSAS’) is found today in churches which teach that after a belief experience, an emotional accepting the Lord Jesus, a person is ‘saved’ and no matter what that person does – even denying Christ a year later, becoming an atheist, even committing murder, that person can never be ‘unsaved’ and has a place in the Kingdom of God (by which they usually understand heaven itself, not the future kingdom on earth). This is also termed ‘free grace’, since no works, and even persistently doing evil works cannot undo salvation. At least this is one response. Others may argue that if someone after being ‘saved’ falls away, then they were never really ‘saved’ anyway. Or both responses may be mixed together.
The teaching is more properly known as the doctrine of ‘eternal security’, taught by John Calvin, where the eternal security of a believer’s ‘immortal soul’ is related to Calvin’s teaching about predestination and the doctrine of ‘perseverance of the saints’, according to which teaching apostasy is impossible for a ‘true Christian’.
A more basic problem
Before going on to show, below, that the Bible clearly teaches that Christians can be saved and then unsave themselves or ‘fall away’, a more basic problem needs to be pointed out: Calvin believed in the immortality of the soul – he believed that a human once born can never be exterminated, destroyed or cease to exist, but must continue eternally without a body either in the traditional medieval ‘heaven’ or ‘hell’. As knowledge among Protestants today that the immortality of the soul is unscriptural is more widespread than it once was, modern variants of ‘once saved always saved’ which try to incorporate a Biblical view of death, as sleep till the last day resurrection can now be found; with those who were saved and denied Christ and committed evil, sleeping, being raised, and being admitted to the Kingdom of God on earth after admonition of some sort. However this is actually less logical than Calvin’s view. For Calvinists the idea of a truly saved Christian soul falling away and a saved soul going to eternal hell-fire (as per medieval tradition) was problematic, and therefore the doctrine of ‘eternal security’ (OSAS) was required. But for those Calvinists who have moved to a Biblical view of death – sleep, resurrection, judgment, reward – what is the logic of Jesus raising and rewarding someone who denied and worked against him? If they now accept that souls are not immortal, why would Jesus do this?
The Bible writers teach that a Christian must continue in belief and practice:
“Not every one that said to me, Lord, Lord, shall enter into the kingdom of heaven; but he that does the will of my Father which is in heaven” (Matthew 7:21).
“If you continue in my word, then are you my disciples indeed” (John 8:31).
The other side of this coin is that the Christian who has been saved can still fall away either by losing faith, denying God and Christ, and also by returning to a life of sin:
“Or do you not know that the unrighteous will not inherit the kingdom of God? Do not be deceived: neither the sexually immoral, nor idolaters, nor adulterers, nor men who practice homosexuality, 10 nor thieves, nor the greedy, nor drunkards, nor revilers, nor swindlers will inherit the kingdom of God.” (1 Corinthians 6:9-10)
19 The acts of the flesh are obvious: sexual immorality, impurity and debauchery; 20 idolatry and witchcraft; hatred, discord, jealousy, fits of rage, selfish ambition, dissensions, factions 21 and envy; drunkenness, orgies, and the like. I warn you, as I did before, that those who live like this will not inherit the kingdom of God. (Galatians 5:19-21)
The Bible is also clear that these people were not ones who ‘were never really saved’, but were truly enlightened and saved, but walked away:
4 For it is impossible, in the case of those who have once been enlightened, who have tasted the heavenly gift, and have shared in the Holy Spirit, 5 and have tasted the goodness of the word of God and the powers of the age to come, 6 and then have fallen away, to restore them again to repentance, since they are crucifying once again the Son of God to their own harm and holding him up to contempt (Hebrews 6:4-6)
20 For if, after they have escaped the defilements of the world through the knowledge of our Lord and Saviour Jesus Christ, they are again entangled in them and overcome, the last state has become worse for them than the first. 21 For it would have been better for them never to have known the way of righteousness than after knowing it to turn back from the holy commandment delivered to them. (2 Peter 2:20-21)
“If we practice sin willfully after having received the accurate knowledge of the truth, there is no longer any sacrifice for sins left.” (Hebrews 10:26)