Although the Pharisees "knew" who Jesus was and why he was able to exorcise demons, they decided to claim he would to cast out demons with Satan, what's the reason why all these Pharisees lost any chance for forgiveness in this life and the next one too (Matthew 12:31-32), because this combination from knowledge and actions is the basis to commit this special sin, which is the only one who takes humans any chance on their hail.
Even mass murderer, who murdered millions of lifes can be saved when he decides to repent, but who "knows" the truth and gainsays it "nevertheless", who decides to turn away from the hail (Hebrews 6:4-6), telling lies, leads humans to the ground (sheoul/hell) as "bad shepherd" (Isiah 11:17), this one has not just sinned, this one is "apostatized" because his decision (1. Timothy 4:1) through his fatal decision and can't be saved again (Hebrews 10:26-27).
When we see the context (Matthew 12:22-32) we see all these Pharisees "knew" they were lost after their blasphemy against the Holy Spirit, what's the reason why they want to to get down as much humans as they can to the ground (like the God of this world and his Rulers of this world, Luke 4:5-7, Ephesians 6:12) with the mantra:"why should anyone has a better eternity than men??"
By the way, that's exactly what Jesus has to reproached the Pharisees (Matthew 23:13) and at first it's terrifying to think about, there're humans in our times too who're lost as the Pharisees for the same reason (Matthew 16:26) and who try for the same reason to share this terrible eternity with as much humans as they can to get down, because they don't want to permit others they have a better eternity.These ones are the most dangerous people on the world, because they to threaten your eternity with false teachings, not just your "limited life" (Matthew 10:28) with their "false teachings", so these wolves in sheepskin are to find in christian circles too, what the bible is warning for more often (2. Timothy 4:3-4, 2. Corinthian 4:4, Jude 3-4, Matthew 7:15).
Lastly, after I've envisaged the most powerfull puppets of the Rulers of this world (Ephesians 6:12) and it's clear why it's so important to know the holy scripture which enemies try to falsify more often (Galatians 1:8-9) I wanted to mention a challenge which atheists started some years ago.These people wanted to proof they're atheists which say bad things about the Holy Spritit and thought this would be "blasphemy against the Holy Spirit".Well, it's not, although it's bad to insult it, but anyone who's not a Christian and who don't believe in Jesus Christ, who never experienced this truth completely and "knew" them, this one isn't able to make this sort of Blasphemy, so all these people - when they live after this action - can be saved despite all their insults in "this life" and I think they should know too "what" blasphemy against the Sprit means, before they start Challenges like this one, during it's one of our (Christians) missions to save as much of them timely, before it's too late for this.