That is a very important question that most ignore how deep this goes.
The problem because 'what constitutes blasphemy of the holy spirit'? This turns out to be much more than word, and in many many cases it is a matter of deed, action.
I have defined some things personally, i.e. this is not accepted by the world in general. Here it is:
There exist: faith, no faith, anti-faith (or negative faith)
Under this subject we have sin which cannot be avoided since we are imperfect sinners; this may be forgiven. It may even be done on purpose in the heat of the moment. The Judge judges this. Thus Judas remains un-forgiven and Peter forgiven.
There is the practice of sin, which damns according to scripture. This is serious sin, deliberately indulged in, repeated as a practice without any intention to repent - that is what damns.
In scripture, God killed those who had no faith in him:
Psalm 106:24-26
24 And they got to contemning the desirable land; They had no faith in his word. 25 And they kept grumbling in their tents; They did not listen to the voice of Jehovah. 26 So he proceeded to raise his hand [in an oath] concerning them, That he would make them fall in the wilderness,
Those who have anti-faith are those who know God exists, but choose to work directly against his will and plans, these are God's adversaries, satans, devils, fallen angels are among them and humans too. Not all fallen angels may be part of them.
James 2:19-20 19 You believe there is one God, do you? You are doing quite well. And yet the demons believe and shudder. 20 But do you care to know, O empty man, that faith apart from works is inactive?
These commit the blasphemy of the holy spirit by being in direct opposition to his word, his will, his plans. Even if they do not utter blasphemous words or sentences, their acts are blasphemous.
I cannot claim that having no faith is blasphemous. That is up to Christ to judge as God's judge. Perhaps some may be forgiven. I know of some who had reason for their loss of faith; some whom I thought were saintly but who suffered terribly.