LOL, that's not even scripturally correct. He doesn't know his own faith! 😂 This is common, and really sad when you think about it, because their faith is their "single most important thing" in life & they're so damn ignorant of it. Like...it's one book. Read it, if you are so inclined?
There is only one sin earmarked as the eternal sin, the unforgivable sin. Explicitly described in Matthew 12:30–32, alluded to in other relevant passages. "Blasphemy of the Holy Spirit". Even blasphemy against the Son of Man (Jesus) will be forgiven...but never the Holy Spirit. Because it's simply too big of a contradiction or discrepancy in how the Christian faith operates & how one is saved. You have the "power of the Holy Spirit" working through you, working with Christ & God the Father on your behalf. Blasphemy against the Holy Spirit is largely interpreted as to deny that very power, the power that saves.
It is akin to needing hydration, but refusing to drink large amounts of any kind of liquid ever. Or needing an electrical charge to run a device, but never making a connection to transfer the power, you're going to somehow "will" or speak the power into your phone. Well. That's simply not how it works, and you'll never have power.
I only explain to provide clarity of the Christian faith to others, I do not profess the faith present day, it has taken 25 years of my life. Others are welcome to comment, of course, but I'm not here to argue endlessly over "how many angels can dance on the point of a very fine needle". As they say, and have done before, and has since morphed more colloquially into "on the head of a pin". 😉
Cursing the holy spirit is not blaspheming the holy spirit.
The only way to blaspheme the Holy Spirit is to have the Holy Spirit move through you, where you know beyond any shadow of any doubt that the essence of God itself is working in your actions, to be purified and elevated above mankind, and then to claim that this purification, elevation, and miracle comes from the devil and not from God.
It is very difficult to do this, and even then, Jesus himself said you would be in danger of Hellfire, not guaranteed to go to Hell forever.