If the trinity is real and all three are the same triune being, then why can you be forgiven if you blaspheme Jesus but not the holy spirit? Aren't they the same person?
You live, and are forgiven like all of mankind. You're only able to blaspheme according to ignorance and/or insufficiency.
If you know you will burn your hand on a hot stove, when you touch it, but you do it, what happens? You get burned. You blasphemed the Spirit of truth even before you touched it. You will be burned, assuming you are able and willing to do so.
Stupid will always be stupid. However, humans may lie, and then revert to the truth again. We evolved from simpler complexity into greater organisms and organizations. We start in many instances from ignorance, which is vindicated, and then progress into knowledge.
Blaspheming your fellow man is natural and forgivable. Blaspheming God is natural, and always forgiven. But blaspheming the Spirit of truth, which is the highest power, results in ignorance without fail.