What you are describing, does not take into account that a believer can have a faith crisis, and their faith is broken.
Or they can "fall from Grace", and literally stop believing that Jesus keeps them saved, and thereby they become a SELF Saver, who is now trying to stay saved, or even "get saved again".
So, there are millions of believers , born again, with NO Assurance of Salvation.
ZERO.
Just ask them on this forum, if the believe they can "lose their salvation", and you have found a believer who no longer believes in anything except their works, and trying to be "be like Christ".
They will talk about keeping commandments as a REQUIREMENT, to go to heaven.
Or water baptism.
Or, "enduring to the end".
They will tell you exactly what is on their LIST that they BELIEVE they have to DO, if they want to go to heaven, OR< stay out of hell., which is really the same broken faith, belief system.