There is no such thing as "the gift of initial salvation".
There is no such thing as "the gift of initial eternal life"
There is no such thing as "initiially born again".
There is LOST or SAVED.
Born again, or not.
Salvation is not temporary, and its not related to your BEHAVIOR.
God's acceptance of us, is only based on what Christ has "FINISHED" on the Cross.
That is our Salvation, it was FINISHED, 2000 yrs ago, and it is Appiled to you if you believe.
Jesus says in John 12:48, “He that... receiveth not my words, hath one that judgeth him: the word that I have spoken, the same shall judge him in the last day.” Meaning, if we do not accept the words of Jesus on what He tells us to do, those words will judge us on the last day.
For example: If we don't believe Matthew 6:15, and we don't forgive others, then Jesus will bring to light the Word of Matthew 6:15 to us in how we will not be forgiven by the Father (i.e. we will not be saved and we will be cast into the Lake of Fire).