"All sins will be forgiven except blasphemy against the Holy Spirit"

Scripture: Mark 3:22-30
What is the unforgivable sin which Jesus warns us to avoid? Jesus knows that his disciples will be tested and he assures them that the Holy Spirit will give them what they need in their time of adversity. He warns them, however, that it's possible to spurn the grace of God and to fall into apostasy (giving up the faith) out of cowardice or disbelief. Why is blasphemy against the Holy Spirit reprehensible? Blasphemy consists in uttering against God, inwardly or outwardly, words of hatred, reproach, or defiance. It's contrary to the respect due God and his holy name. Jesus speaks of blaspheming against the Holy Spirit as the unforgivable sin. Jesus spoke about this sin immediately after the scribes and Pharisees had attributed his miracles to the work of the devil instead of to God. A sin can only be unforgivable if repentance is impossible. If someone repeatedly closes his eye to God and shuts his ears to his voice, he comes to a point where he can no longer recognize God when he can be seen, and when he sees evil as good and good as evil (Isaiah 5:20). To fear such a sin, however, signals that one is not dead to God and is conscious of the need for God's grace and mercy. There are no limits to the mercy of God, but any who refuses to accept his mercy by repenting, rejects the forgiveness of his sins and the salvation offered by the Holy Spirit.