I would agree with instances where the person is guilty of multiple mortal sins. Like a guy who raped twenty girls and does not want to stop. Such a person we could almost with certainty state he is ''sold out to the darkness'' per John 3:19. Those guilty of once off mortal sins, I don't think so. We can all be guilty of such. David loved God and yet murdered (once) and committed adultery (once I think). But he knew and the people knew, these were sins unto death / deserving of death. His repentance to God had to be very sincere to make amends. Which I believe it was.As a side-note -- my personal opinion -- a life with no parole sentence Should be changed to death penalty. And That should be carried out quickly.
This is why I say, mortal sins point to our love of sin. That is my only reason for raising them. I am discerning / judging by fruits as Jesus says I should.
They have labelled it mortal and venial. Most know it as grievous and non grievous. Any church that teaches you can lose your salvation does by default categorize sin. The church I attend will remove from ''open teaching'' and perhaps if severe, even fellowship anyone guilty of sins like adultery and drugs. Let alone murder and rape.It's the RCC that categorizes all of them into either mortal or venial sins. No one else does.
Then I would also argue, we ''ALL'' categorize sin. Let's say a Christian girl married a Christian guy. The Christian guy thought of adultery. Would she divorce? No. Let's say the Christian guy actually committed adultery, would she divorce? Perhaps. Let's then say the Christian guy, committed adultery with many woman, would she divorce? She should.
Matt 5:28 = thoughts of adultery are sinful.
Matt 5:32 and Matt 19:9 = Only divorce if there is actual adultery