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 their eyes to God, shuts their ears to his voice, and reject his word, they bring themselves to a point where they can no longer recognize God when he can be seen and heard. They become spiritually blind-sighted and speak of “evil as good and good as evil” (Isaiah 5:20)