Unforgivable Sin
<<unpardonable>>
Jesus had performed a miracle in the power of the Holy Spirit, and was accused by the Pharisees of being possessed by a demon. In spite of the evidence they stubbornly refused to recognise Him, deliberately insulting Him. Jesus termed this blasphemy or defiant irreverence the unforgivable sin – slandering the Holy Spirit in the context of His work in the world through Christ – but stated forgiveness is granted to anyone who repents for speaking against Jesus (Mt 12:22-32; Mk 3:22,28-30; Lk 12:10). Some commentators consider this blasphemy against the Holy Spirit was specific to when Jesus was on earth as no one can personally see Jesus perform a miracle and then attribute that power to Satan instead of the Holy Spirit.
Anyone who seeks forgiveness and repents will be forgiven
conviction, so if they have such thoughts they should confess them to Jesus, repent, and accept forgiveness.
Meanwhile the unsaved, rejecting the promptings of the Holy Spirit shut themselves off from the only means that can lead to repentance, forgiveness and restoration to God and so condemning themselves to spiritual death, an eternity in hell because of unforgiven sin. The only unpardonable sin today is that of continued unbelief in Christ which includes denying the work of the Holy Spirit in convicting them of sin, righteousness and judgment (Jn 16:7-11). There is no pardon for a person who dies in unbelief and unforgiveness, having resisted and rejected the Holy Spirit, and never asked and received the cleansing power of the blood of Christ for sin. God has provided for our salvation in His Son, and as Jesus is the exclusive source of forgiveness and salvation to die without His pardon is thus unpardonable (Jn 3:16,36, 14:6; 1 Jn 5:11,12).
When we initially turned to Christ at salvation this dealt with the sin nature, that if left unaddressed takes unrepentant sinners to a lost eternity of eternal damnation. Since conversion we still often sin, and while not affecting our eternal destiny, this will have an impact on our relationship with the Lord (Ps 66:18).
See also: blasphemy, confession, conscience, conviction (2), forgive/forgiveness, Holy Spirit, repentance, sin/sinner, unbelief, unforgiveness.