Ezekiel chapter 18 would be a better reference to contradict the teaching of OSAS.
One is saved as long as you remain faithful to God. Choosing your destiny is a personal choice, and one that you must make daily.
The biblical teaching on salvation is better expressed as “once saved always saved as long as you stay saved”. ie, as long as you abide in him.
The OSAS philosophy is closely linked to the teaching of predestination. Predestination is the teaching that God chooses, or has already chosen who will and who will not be saved.
If you are not saved, it is because God did not choose you. In other words, it is not your fault, it is God’s fault. As soon as you head down this path you realise exactly who it is that originally blamed God, and that if you follow this teaching you are following him and not God.
Man has been given free will. Each is to choose his own destiny, or as Paul put it, work out your own salvation with fear and trembling.
Speaking of himself Paul also said “Not that I have already attained, or am already perfected; but I press on, that I may lay hold of that for which Christ Jesus has also laid hold of me.”
If Paul does not take his salvation for granted, but picks up his cross daily, and strives that “if, by any means, I may attain to the resurrection from the dead”, then we must do the same.
Frequently the idea that you are not saved unless you remain saved is spoken against as being false because then you have no joy in assurance of your salvation. This is like the Pharisee who prayed loudly to God looking up to heaven and thanking him for his salvation, and that he was not like the publican. The publican however beat his chest and would not even look up to heaven and prayed, “God, forgive me for I am a sinner.”
The prayer of the publican has always been unpopular, and is becoming even more unpopular of late.