Our use of the term “unforgivable sin” is the common usage, which refers to a personally irreversible hardening of one’s heart against God’s commander over the hearts of people, the Holy Ghost. While forgivable sin is simply an opposition to the commandment of God, unforgivable sin is also an opposition to the commander of God, the Holy Ghost.
Now, what about Matthew 12:32, which says, in part, “…it shall not be forgiven him, neither in this world [not in this life]….”? Doesn’t that mean that being alive and not in hell is not enough to prove that one has not committed an unforgivable sin? No, because Matthew 12:32 is talking about doing more than committing an unforgivable sin. Let’s look at the context. Matthew 12:31-32 says:
(31) Wherefore I say unto you, All manner of sin and blasphemy shall be forgiven unto men: but the blasphemy against the Holy Ghost shall not be forgiven unto men.
(32) And whosoever speaketh a word against the Son of man, it shall be forgiven him: but whosoever speaketh against the Holy Ghost, it shall not be forgiven him, neither in this world, neither in the world to come.
Verse 31 talks about the unforgivable sin of “blasphemy against the Holy Ghost.” Verse 32 talks about the unforgivable sin of speaking against the Holy Ghost (“speaketh against the Holy Ghost”). Speaking against the Holy Ghost is, when it is your last chance to be forgiven, committing an unforgivable sin that knowingly influences another person, by your word and/or deed, to reject Christ, by their word and/or deed. Note that this knowingly influencing must be deliberate, not automatic and not merely through weakness of character. As a footnote, we ask, “Why does God tell us that this sin won’t be forgiven in this life?” It would give some an incentive to learn what God has to say about unforgivable sin.