Many view the word forgive, as used in the Bible, in a way that may not be correct, as discussed by Talbott in The Inescapable Love of God . Here are the New Testament occurrences of the words forgive, forgiven, forgiveness, and the related word pardon.
“But if you do not forgive others, then your Father will not forgive your transgressions.” (Matthew 6:15)
“Whoever speaks a word against the Son of Man, it shall be forgiven him; but whoever speaks against the Holy Spirit, it shall not be forgiven him, either in this age or in the age to come.” (Matthew 12:32)
“My heavenly Father will also do the same to you, if each of you does not forgive his brother from your heart.” (Matthew 18:35)
“but whoever blasphemes against the Holy Spirit never has forgiveness, but is guilty of an eternal sin” (Mark 3:29)
“But if you do not forgive, neither will your Father who is in heaven forgive your transgressions.” (Mark 11:26)
“Do not judge, and you will not be judged; and do not condemn, and you will not be condemned, pardon, and you will be pardoned.” (Luke 6:37)
Merriam/Webster defines the word forgive in several ways. The definition that leads to confusion is “to give up resentment of.” People interpreting these verses with that definition in mind often conclude that one’s salvation is impossible if one is not forgiven, for God will never give up resentment of such a sin that is not forgiven. Thus, they conclude that one can do nothing to gain salvation if one is not forgiven. That would seem to deal a lethal blow to concept of universal reconciliation.
But Merriam/Webster also defines the word forgive as “to grant relief from payment of.” Similarly, it also defines the word pardon as “to allow (an offense) to pass without punishment.” These definitions cast a different light on the issue of salvation. For using these definitions, one can easily see that salvation is still attainable even if one is not forgiven or pardoned. It would be attainable if one could somehow pay for one’s sins, for example through punishment.
Does the Bible shed light on this issue? Yes it does, and it seems to favor the concept that forgive is based on the idea of relief from paying a debt. Consider these key verses.
“My heavenly Father will also do the same to you [i.e., hand you over to torturers until you repay all that is owed, from Matthew 18:24], if each of you does not forgive his brother from your heart.” (Matthew 18:25)
“For while you are going with your opponent to appear before the magistrate, on your way there make an effort to settle with him, so that he may not drag you before the judge, and the judge turn you over to the officer, and the officer throw you into prison. I say to you, you will not get out of there until you have paid the very last cent.” (Luke 12:58-59)
“Make friends quickly with your opponent at law while you are with him on the way, so that your opponent may not hand you over to the judge, and the judge to the officer, and you be thrown into prison. Truly I say to you, you will not come out of there until you have paid up the last cent.” (Matthew 5:25-26)
“Now where there is forgiveness of these things, there is no longer any offering for sin.” (Hebrews 10:18)
So it appears that salvation is still attainable even if one is not forgiven or pardoned. It would be attainable if one pays for one’s sins. That payment could well be what Paul alluded to in 1 Corinthians 3:15.
“If any man’s work is burned up, he will suffer loss; but he himself will be saved, yet so as through fire.”
Thus, unforgivable or unpardonable may not necessarily mean uncorrectable when it comes to debts in this world or to sins in the next.