That still changes nothing when we're considering whether predestination is scriptural or not.
If a believing Christian comes to a point in their life, whereby they no longer believe, then they would stop confessing their sins, and would not be forgiven of those sins, nor cleansed of their unrighteousness.
Therefore I said to you that
you will die in your sins;for if you do not believe that I am
He, you will die in your sins.”
John 8:24
If we confess our sins, He is faithful and just to forgive us
our sins and to cleanse us from all unrighteousness.
1 John 1:9
3 Now
by this we know that we know Him, if we keep His commandments. 4 He who says, “I know Him,” and does not keep His commandments, is a liar, and the truth is not in him.
1 John 2:3-4
"Knowing Him" is the definition of eternal life.... And
this is eternal life, that they may know You, the only true God, and Jesus Christ whom You have sent.
John 17:3
This is how we know that we know Him...
by this we know that we know Him, if we keep His commandments. 4 He who says, “I know Him,” and does not keep His commandments,
is a liar, and the truth is not in him.
Knowing Him is eternal life, the thing you label as "fellowship", is the text book, biblical definition of eternal life.
The way the bible has given us to verify and prove that we know Him is:
by this we know that we know Him, if we keep His commandments.
There is a condition to having eternal life... it is keeping His commandments, the evidence of knowing Him.
If we stumble in this, we can confess our sin and be forgiven, as we have an Advocate with the Father...
If we say that we have no sin, we deceive ourselves, and the truth is not in us.
If we confess our sins, He is faithful and just to forgive us our sins and to cleanse us from all unrighteousness. If we say that we have not sinned, we make Him a liar, and His word is not in us. My little children, these things I write to you,
so that you may not sin. And if anyone sins,
we have an Advocate with the Father, Jesus Christ the righteous. And He Himself is the propitiation for our sins, and not for ours only but also for the whole world.
1 John 1:8-2:2
The Test of Knowing Him
3 Now by this we know that we know Him, if we keep His commandments. 4 He who says, “I know Him,” and does not keep His commandments, is a liar, and the truth is not in him.
That's why the Apostle Paul, constantly warned the Gentiles, who were used to living in immorality, not to practice the works of the flesh, because it would end up resulting in them being partakers of God's wrath on the day of judgement.
Paul warned them over and over of these things.
5 For this you know, that no fornicator, unclean person, nor covetous man, who is an idolater, has any inheritance in the kingdom of Christ and God. 6 Let no one deceive you with empty words, for because of these things the wrath of God comes upon the sons of disobedience.
7 Therefore do not be partakers with them. Ephesians 5:5-7
Let no one deceive you with empty words...
JLB