Summary: In dealing with both Christians and non-Christians I have heard people say, “I am afraid that I have committed the unpardonable sin, and therefore there is no hope for me. I can’t be forgiven.” What is the unpardonable sin? Who can commit it?
In dealing with both Christians and non-Christians I have heard people say, “I am afraid that I have committed the unpardonable sin, and therefore there is no hope for me. I can’t be forgiven.” What is the unpardonable sin? Who can commit it? In answering this we must look at three sins mentioned in the Bible – blaspheming the Holy Sprit, rejection of the Holy Spirit, and habitual willful sin despite the Holy Spirit.
I. The Blaspheming of the Holy Spirit
A. A sin that was committed during the earthly ministry of Jesus Christ
B. Jesus presented himself to Israel as the King, the Messiah, the Anointed One, the fulfillment of all Old Testament prophecy. When the crowds began to consider that He might be Who He claimed He was, the Jewish leadership rejected His claims and asserted that Jesus Christ was demonic and attributed the power behind His miracles not the Holy Spirit but to Satan.
D. The religious leaders of Israel had the full revelation of all the Messianic prophecy of the Old Testament right before their eyes. Christ was the fulfillment of all that had been foretold. In spite of that full revelation they rejected Christ and concluded it was not the Holy Spirit at work in Christ’s ministry but Satan.
F. Christ response to this charge was soul chilling.
G. Mark 3:28-30 (quickview)  “Assuredly, I say to you, all sins will be forgiven the sons of men, and whatever blasphemies they may utter; but he who blasphemes against the Holy Spirit never has forgiveness, but is subject to eternal condemnation because they said, "He has an unclean spirit.”
H. This sin of blaspheming the Holy Spirit was a historic thing. It was committed at a very specific period in time by some specific people who specifically attributed the observed manifestation of the deity of Jesus Christ through His miracles and message to Satan. The blasphemy against the Holy Spirit was the conscious and deliberate rejection of the saving power and grace of God observed through Jesus’ ministry. It is not something that can be committed today.
II. The Rejection of the Holy Spirit’s Final Call
A. God’s Holy Spirit calls lost men to repentance and salvation.
B. John 16:8-10 (quickview)  “And when He has come, He will convict the world of sin, and of righteousness, and of judgment: of sin, because they do not believe in Me; of righteousness, because I go to My Father and you see Me no more.”
C. The Holy Spirit knocks at the heart’s door of each person who is not saved. When the Holy Spirit knocks on your heart that is called the conviction of the Holy Spirit. When a person is not saved he or she is convicted by the Holy Spirit of their sin and their need of Jesus as their own personal Saviour before conversion.