Within the camps of Eternal Security believers, there lies in this corner Once Saved Always Saved (OSAS) and in this corner Perseverance of the Saints (POTS). At face value one might assume that they mean the same thing just different terminology. But that, my friend, would be an incorrect assumption, for they are very much different. Whereas the ends may meet as the individual crosses over into glory unable to lose his salvation, the means or actions by which he took while on this trip up the narrow road is indeed different.
For the sake of length and clarity, I will do my best to simplify both corners without a multitude of words. This is not a defense of either, but a simple act of trying to show that by no means are they the same. Please feel free to express your thoughts and correct me if you believe my understanding to be wrong.
Once Saved Always Saved (OSAS)
This position holds that a person may be genuinely saved by Christ and become a born again believer. Although saved, one may then return back into their fallen sinful state as if they had never been regenerated. They may have a lifestyle of the unsaved, yet because at one point in their life the trusted Christ, regardless of how they live their life or die, they are saved forevermore. An example would be while witnessing to a person they bow their head and ask Christ to save them, yet they never come to church or display any Christian qualities for the rest of their lives. This position claims that “if they really meant it”, then regardless that they never acted as a Christian, they are indeed one by virtue of them at one point in their life asking Christ to save them. No one can 100% say that they are saved or are not saved, by ones actions, for only God knows our hearts and if someone has actually asked Him to save them then they are indeed saved.
Perseverance of the Saints (POTS)
This position agrees that a person is genuinely saved by Christ and becomes a born again believer. It also agrees that nothing, including sin, can separate a believer from the love of God and that it is impossible for one to fall from grace. Where this camp disagrees is that a true believer cannot and will not return to or remain in their previous unregenerate lifestyle. Not that a believer will be sinless, but that their lifestyle will become and remain that of a person striving to serve God, rather than that of a lost person disobeying God. It is not the individual which causes this, but the working of God within them. Lifestyle of the believer appears to be the difference. Because of the work of God within them, the believer’s desires shall be to serve God, even though they may faultier, yet they never turn to rejection of God, or a total non-desire, and back into their depravity. Although they may agree no one can know 100% who is and is not saved, one can know them almost positively by their fruits, their works and lifestyle.