There are three instances in the gospels where Jesus labels a sin as “unforgivable,” and in each instance the sin Jesus refers to is speaking against/blaspheming the Holy Spirit. In Matthew 12:22-32, Jesus refers to “speaking against the Holy Spirit” in verse 32, after casting out a demon. In Mark 3:29, Jesus speaks about “whoever blasphemes against the Holy Spirit,” after being accused of being possessed by the demon Beelzebub. And in Luke 12:10 Jesus refers to “whoever blasphemes against the Holy Spirit,” while exhorting his followers to be bold in their confession before others.
While all three instances refer to some sort of rejection or blasphemy of the Holy Spirit, scholars have often debated the precise definition of what it means to “blaspheme the Holy Spirit.” Most, however, seem to have come to a similar conclusion, one with which I tend to agree: Blasphemy of the Holy Spirit is a refusal to acknowledge God’s actions as God’s actions.
It’s the sin of selfishness that says, “God didn’t do this. I did!” It’s the sin of rejection that says, “God isn’t responsible for the good things of the world.” It’s the sin of refusing to accept the love of God as fulfilled in Jesus. In short, the only sin that is unforgivable is the constant rejection of God, the refusal of grace, forgiveness and love.
Chris Thomas, First Baptist Church of Williams
There is no unforgivable sin
God says in the Quran: “Say: ‘O my people who have transgressed against their souls! Despair not of the Mercy of God: for God forgives all sins: for He is Oft-Forgiving, Most Merciful’”(39:53).
The words “all sins” is my hope if I commit a sin. In Islam there is no unforgivable sin. The most heinous sin is polytheism, worshiping any one besides God or with God. Even this sin is forgivable if one makes repentance and asks God for forgiveness before death. If we have committed sins against people, Islam teaches that we should ask forgiveness from the people and compensate their loss before we ask God for forgiveness.
Sins are categorized in Islam into major and minor. Minor sins are common mistakes like forgetting a promise or being rude to others. These minor sins are forgiven by God whenever we do something nice like praying to God, helping the needy or volunteering for a good cause for the sake of God.
What is dangerous are major sins like worshiping anyone other than God, not doing the obligatory prayers, adultery, fornication, disrespecting parents, drinking alcohol, gambling, etc. If a believer is really ashamed of a major sin and cries to God for forgiveness and commits not to do it again, God forgives these major sins also. God is so merciful and forgiving that we end up getting all the sins forgiven with proper repentance and making a good promise to God.
Muhammad Haq, Anniston Islamic Center