What is blasphemy of the Holy Spirit?

Summary

The sermon discusses the sin against the Holy Spirit, contrasting historical Puritan views with modern interpretations. While some believe the unforgivable sin is simply unbelief at judgment, the speaker leans towards the Puritan idea that it's a conscious rejection of the Spirit's work, exemplified by the Pharisees accusing Jesus of working by the devil's power. The takeaway is to be wary of deliberately maligning the Holy Spirit's work after acknowledging Jesus as Christ.