If you are going to believe in OSAS then believe in it all the way and accept what it means. It means simply that once a person has been truly born again, then nothing they do or don't do can ever make them lose their salvation. That means that if a truly born again person sins like Hitler he will still go to heaven. Even if he curses and swears and tells God he doesn't want to go to heaven, he will still go to heaven.
Ever heard of Charles Templeton? He was a world class evangelist who mentored a young Billy Graham. in 1947 they roomed together while traveling through Europe holding crusades.
Later on, he believed something (that wasn't true) that didn't square with reality, and concluded that God didn't exist. So this evangelist, who had led thousands, even hundreds of thousands to Christ, became an atheist. Not one of your run of the mill "activist-type" atheists, but an atheist just the same.
Here is the fact about salvation. The gift of eternal life is received (given by Jesus Christ-Jn 10:28) WHEN a person believes in Christ (Jn 5:24). So from the moment of saving faith in Christ, that person possesses eternal life, so that that person shall never perish.
There are 2 verses that explain very clearly who will be condemned:
John 3:18 - Whoever believes in him is not condemned, but whoever does not believe stands condemned already because they
have not believed in the name of God’s one and only Son.
2 Thess 2:12 - and so that all will be condemned who
have not believed the truth but have delighted in wickedness.
The bolded words are in both verses. So, what do they mean? They refer to those who have NEVER believed, which is the same thing as "have not believed".
There is no time frame referenced, so the verses obviously include the entire person's life.
So, if one has NEVER believed, they WILL BE condemned.
But, if one has EVER believed, they SHALL NEVER PERISH. Because they were given the gift of eternal life.
Very simple.
It is amazing that Arminians keep trying to make things difficult.
If you are going to believe in OSAS, but don't want to believe the previous paragraph you have two basic options:
(1) Teach that the believer no longer has a free will (or a moral capability to deny God) and thus cannot/will not choose to not believe
(2) Teach that God will chasten and discipline the believer who is faltering, but if necessary will kill him (the sin unto death) before he becomes an unbeliever
Only #2 is correct.
We know that #1 cannot be true since Jesus Himself described the second soil as one who "believed for a while" but when testing/temptation came, "fell away". (quit believing)