So, if I’m understanding you, you can commit any and all sin, not confess any and also be completely unrepentant of same...
And still be with God in heaven?
Red herring because someone with that attitude is not saved.
I and others have said it before and I'll say it again.
No believer believes that their security is a license to sin.
Salvation is not fire insurance. It's a restored relationship with the living God which is manifest in a changed life because the person has a new nature.
So if we miss confessing some sin because we forgot or didn't realize that we had sinned (unintentional sins) then we're covered anyway.
Even if we sin deliberately, there is still the issue of God dealing with it here on earth. God chastises those he loves and disciplines us for our own good. No believer, even if they sin deliberately, is getting away with anything.
At the most extreme, God will ensure an early death before losing someone.
God WANTS to save us. He's not looking for excuses to damn us. We're already damned because of our sin. He's basically looking for excuses (if you will) to save us, hence His grace and mercy.
Repentance is simply changing our thinking back towards Him. All throughout the Old Testament Prophets, where it is reiterated: "Return to God, so He may return to you!", we see a similar relationship.
When we return to God, it is through faith in Christ. Specifically, it is of His work on the Cross to which we think in salvation.
We use the phrase, faith alone in Christ alone, to help reiterate the object of our thinking.
When we focus upon Him and His work on the Cross, we recognize the sin we committed, known or unknown, was imputed on Him on the Cross and has already been judged.
That judgment is over.
We still are still His once we have salvation. No amount of sin will remove that relationship, because sin has already been judged at the Cross.
We confess those sins, evidence our faith by an action of our heart, not merely our mind, and He is sure and just to forgive us those sins. Our perspective of our relationship with Him is re-established by 1stJn1:9.
It isn't as if the post-salvation sin is new to God. He knew each and every one that will ever be committed when He was imputed with them on the Cross.
He doesn't do anything that is good for nothingness. When He first saved us, He already knew of every sin we would ever commit. Forgiveness of past sins occurred at the moment of salvation, and from our perspective, the forgiveness of postsalvation sin occurs at the moment we turn back to Him and confess them to Him.