Justification is the act of salvation from God who makes the judgement.
This does NOT change.
When other scriptures talk about falling away it is not from justification, it is from grace which is different.
I really like how this man has defined grace,
Michael Horton
writes, “In grace, God gives nothing less than Himself. Grace, then, is not a third thing or substance mediating between God and sinners, but is Jesus Christ in redeeming action.”
Grace is mercy not merit.
When we fall from grace we leave the place of closeness with God, grace ties us to Him, but because
we do have ability to choose there are times when we stumble, loose faith, fall into sin, but God has declared us justified, we are not going to hell.
We recognize that we have fallen from grace and renew our minds so that we once again we abide in the vine. There is repentance in that for sure
but is not a repentance to gain back a saved status!!!
A born again believer is never to be condemned to hell, God does not change His declaration or our status.
You need to see it from His vantage point not the human one.
Your really need to make this distinction, I hope you will,
this is gospel, not the butchered version of some of the post reformers of the 16th century .
The failure is to take ALL of the NT verses into account.
IMO, God's grace is given initially to the born-again believer.
But, he can fall from grace ... one cannot fall from something he does not already have!
He can be estranged from Christ ... one cannot be estranged from something he does not already have!
Another question to ponder ...
Those who fall away from the faith -- have they fallen away from salvation?
IMO, if they repent, they can be reinstated back into the faith again --
back into a saved state again.
Perhaps all of the dire warnings are to produce such a result as this.