People caught up in sins and sexual immorality, if they die unrepentant, as in obstinately refusing God's command's, like stiff necked, then they are still dead in their sins, as they are resisting the Holy Spirit. Paul resisted the Holy Spirit until he could no longer, God overwhelmed his soul and he then was forever changed.
People who turn back, look back are not pleasing to God, are not fit for God's kingdom, so then not saved, like Lot's wife who then was not delivered from the destruction of Sodom because they are not really born again.
Luke 9:62
But Jesus said to him, “No one, having put his hand to the plow, and looking back, is fit for the kingdom of God.”
People who are not born again, will look back , turn back to their old ways!
their is such a thing as an apostate
2 Peter 2
21 For it would have been better for them not to have known the way of righteousness, than having known
it, to turn from the holy commandment delivered to them
22 But it has happened to them according to the true proverb: “A dog returns to his own vomit,” and, “a sow, having washed, to her wallowing in the mire.”
A person can see the path to eternal life, but never go down it, but they know it is there, so they would have know the way of righteousness.
And for all that, we are only saved if we persevere in faith until the end.
Hebrews 3
5 And Moses indeed was faithful in all His house as a servant, for a testimony of those things which would be spoken afterward, 6 but Christ as a Son over His own house, whose house we are if we hold fast the confidence and the rejoicing of the hope firm to the end.
Hebrews 9
27 And as it is appointed for men to die once, but after this the judgment, 28 so Christ was offered once to bear the sins of many. To those who eagerly wait for Him He will appear a second time, apart from sin, for salvation.