From my Christian pov that sin only accrues to a person who by a true (ie, not while enslaved to sin already) free will chooses to rebuke YHWH as a false god (the reprobate) or who disobeys HIM while accepting HIM as their GOD (the sinful elect, HIS sheep gone astray into sin, the sinful people of HIS kingdom).
I don't accept that some sins are forgiven because HE hates them less than other sins because I believe any every, each and all sins have an equal and ultimate disvalue in HIS sight. HE created us for a reason and with a free will to be able to fulfill that reason and any disruption to the fulfillment of that reason must either be cured or destroyed or HIS purpose will never be fulfilled, ie, HIS creation married with HIM.
Iow, the reason some sins are forgiven and some are not, lies in the person being forgiven and some people being outside of HIS mercy and grace by their own free will.
What choice can a person make that causes GOD to hate them, putting themselves outside of HIS loving care and forcing HIM to banish them to the outer darkness?
Unforgivable sin, the Satanic fall:
The unforgivable Sin
From my Christian pov, the unforgivable sin was the Satanic fall, their free will decision to reject by faith, ie, an unproven hope, YHWH's unproven claims to be our creator GOD and to reject the gospel of salvation from sin as found only in the Son. It contained the ideas that HE was no better than the rest of us so HE must be a liar and as a liar, a false god...just listen to atheists and pagans about their opinion of HIM for confirmation.
As the first liar in all of creation, HE must therefore be the most evil person in existence so they repudiated HIM, rejecting HIM from having any influence in their lives at all. Putting their faith in this idea that HE was evil and driven by a psychotic megalomania made them eternally unfit to ever be HIS Bride so they were condemned to judgement on the spot, passed over for election to salvation due to their choice.
They can't be forgiven because
1. they made the decision to rebel against GOD's claims to Deity by their free will and a free will decision cannot be changed by anyone, even GOD, unless the person asks for it to be changed. All free will decisions must be sacrosanct and inviolable and apart from GOD's interference or it cannot be defined as free. This is not a rule but a matter of definitions: A cannot be not A at the same time; wet cannot be dry at the same time; free to choose an unchangeable decision can't therefore be changed by another and still be considered free.
2. Once they rebelled they became enslaved by the addictive power of evil which destroyed their ability to seek true repentance and unable to save themselves by changing their minds about HIM. They were instantly and totally unable to repent of their evil and became even more committed to the belief that they were right to rebel against this upstart liar and false god. So great is their addiction to evil that even after they learned the truth of HIS divinity and power when they saw the creation of the physical universe with their own eyes as described in Job 38:7, they could not change their minds because they loved their sin more than the truth as we learn in Roman 1:18+.
This describes the Satanic fall that precipitated the war in heaven and had all sinners, elect and reprobate, flung into the earth, Rev 12:4-9.
They are not unforgivable because HE hates them and their sin so much because it is worse than other sins but because when HE proclaimed HIS gospel of salvation to every creature created in HIS image, Colossians 1:23, for us to accept HIS claims or to reject HIM, HE promised us our choice would not be interfered with or changed or forced upon us without our consent, though there would be legal and natural consequences...warnings explained to everone in full but which some ignored as lies.
The choice to eternally repudiate HIS help in saving them from the grip of sin while becoming unable to save themselves by changing their minds sealed their doom.
HE lovingly gave them the right and the ability to choose their own fate.
HE was fair and righteous to allow them to choose evil after warning them sincerely about the natural and legal consequences for choosing evil.
It was righteous for HIM to not interfere after they made the choice to rebuke HIM as a false god by allowing their free will choice to work out to its end.
They did not want to live with HIM in HIS heavenly marriage so much they chose to repudiated HIM even though they knew that if HE was ever proven to be their GOD, they would be doomed to hell... Iow, they chose to go to hell by their free will rather than ever having to live with HIM in HIS heaven. Alas, that is what they get.
So committed were they to this idea of HIS being a false god, they even ignored the ploy of those who decided to accept YHWH's claims and gospel until HE elected them to salvation as HIS gospel promised so that they were free of all danger of hell if it were ever proven that HE was indeed our creator GOD at which time they planned to go their own way whether HE thought it was a sin or not. As elect what did they have to lose? But the reprobate denounced this bit of theological skulduggery as beneath their faith in opposing HIM eternally, not believing that HE had any power to do anything about it.
Thus, while GOD chooses our LIVES unto our redemption or to hell based upon our own free will choices, we chose our eternal FATES unto redemption or hell by our own free will.
