In Jesus' warning, there was no being saved and then lost, rather never being saved, Matthew 7:21-23.
Matthew 18
23“For this reason the kingdom of heaven may be compared to a king who wished to settle accounts with his slaves.
24“When he had begun to settle
them, one who owed him ten thousand talents was brought to him.
25“But since he did not have
the means to repay, his lord commanded him to be sold, along with his wife and children and all that he had, and repayment to be made.
26“So the slave fell
to the ground and prostrated himself before him, saying, ‘Have patience with me and I will repay you everything.’
27“And the lord of that slave felt compassion and released him and forgave him the debt.
He begged the LORD for mercy. The LORD forgave him. His is SAVED. Debt is clean and GONE.
28“But that slave went out and found one of his fellow slaves who owed him a hundred denarii; and he seized him and
began to choke
him, saying, ‘Pay back what you owe.’
29“So his fellow slave fell
to the ground and
began to plead with him, saying, ‘Have patience with me and I will repay you.’
30“But he was unwilling and went and threw him in prison until he should pay back what was owed.
31“So when his fellow slaves saw what had happened, they were deeply grieved and came and reported to their lord all that had happened.
32“Then summoning him, his lord said to him, ‘You wicked slave, I forgave you all that debt because you pleaded with me.
33‘Should you not also have had mercy on your fellow slave, in the same way that I had mercy on you?’
34“And his lord, moved with anger, handed him over to the torturers until he should repay all that was owed him.
35“My heavenly Father will also do the same to you, if each of you does not forgive his brother from your heart.”
My heavenly Father will also do the same to you, if each of you does not forgive his brother from your heart.”
Thats called a warning and it was directed at PETER and the Apostles.
The common cry is if your a unbeliever or not saved is God will not forgive you at all. So this parable is particularly damning. Because the person here IS FORGIVEN/SAVED.
(No matter how you take this passage who is the THREAT leveled to? Cause even if you claim well thats unsaved folks......its still demanding of proper action from unsaved folks)