Shalom Heresy.
Sorry for my distraction above.
I do have some knowledge.
What is blasphemy against the Ruach HaKodesh? (God's Spirit, Holy Spirit, Holy Ghost)
Long story short, it's an unpardonable sin. My personal answer for you is that to commit the sin you would have to view his spirit as evil, or unclean. Even if say, you knew it wasn't, and you denied the truth because you didn't care, and spoke out against it as evil.
Because they were saying, "He has an unclean spirit" - Mark 3:30.
Since it's a lot to type, for more detail view Matthew 12:22-32 for a much better understanding, and an example. You can also find more relations in Mark 3:21-30.