26 If we deliberately keep on sinning after we have received the knowledge of the truth, no sacrifice for sins is left, 27 but only a fearful expectation of judgment and of raging fire that will consume the enemies of God.
-Hebrews 10:26-27, NIV
Do I think unrepentant adulterous spouses are going to Hell?
I would answer you with a question:
What do you think? How do you read their situation in light of Hebrews 10:26-27 (quoted above)?
-What we know is that a cheater who refuses to repent is thereby deliberately engaging in sin. They are doing this in an ongoing manner.
-If they are professing Christians, they were given saving knowledge about Jesus. That is what made them a professing Christian.
Put those things together and read Hebrews 10:26-27.
Are they going to Hell or a fiery judgment according to the Bible here? Should a unrepentant cheater be concerned?
Ultimately, God makes the judgment and choice in this matter. We can trust Him to be both good and just.
One thing is clear to me, though:
A person who really cares about the eternal destination of an unrepentant cheater has reason for concern.
I like good magic tricks, especially good sleight of hand. Since emotional sleight of hand is one of their love languages, I wonder what trick an unrepentant cheater has up their sleeve for the day of judgement?