Yes, salvation can not be lost! never! nor an any external force can taken away or steal or rob our salvation!
Giving that standard programmed answer “we cannot loss our salvation”, we can tell that they only see one side of the coin. They only talk about external force to take away our salvation, which can not ever possible.
It’s like talking to Russelites about Jesus’ Divinity:
me: Jesus is The Lord God Almighty!
Russelites: here i show you a hundred verses that prove Jesus was human
me: yes i know Jesus was human
Russelites: ok that settle it, we are correct about it
me: the topic is not whether Jesus was human, the topic is whether Jesus is God Almighty!
They failed to see the other side of the coin: abide!
The topic is NOT whether we can loss our salvation. We can never loss our salvation! That settle it once and for all!
The topic is whether we need to abide or can we choose to stop believing in saving-faith and still get saved?
We are commanded to abide!
2John 1:9 Whosoever transgresseth, and abideth not in the doctrine of Christ, hath not God. He that abideth in the doctrine of Christ, he hath both the Father and the Son.
Abide is NOT works! Abide is stay in the faith we are saved.
Apostate is choose to stop believing in the saving-faith. Like some Galatians persuaded to believe in salvation by works. And Paul rebuke them that if they leave the saved-by-grace faith and believe in saved-by-works faith, they are apostate!
And, there are tons and tons of warning if we do not abide and chose to apostate!