Exactly. I have never understood the concept of once saved. It’s wrong.
"For if after they have escaped the pollutions of the world through the knowledge of the Lord and Saviour Jesus Christ, they are again entangled therein, and overcome, the latter end is worse with them than the beginning. 21 For it had been better for them not to have known the way of righteousness, than, after they have known it, to turn from the holy commandment delivered unto them."
It is all of the above and more. It is the starting line, the race and finishing the race strong. In each phase the salvation belongs to God. He is the Author of salvation.
I will also note if the object of our salvation is false to begin with, the finish line will end badly.