Not a 5 pointer - husband is. Why?
On the verse in question, when one gives credit for evil to the H.S. there is a hardening of the heart and, I would argue, a full knowledge that one is doing so. That is not the act of someone who will be coming to Christ. It’s something someone like Madelyn Murray O’Hare would have done (and probably did do). She knew full well, I have no doubt, who it was she was rejecting, but her heart was so hardened she was in full rebellion and gave herself over to evil. Again, if one is coming to Christ or leaning that way, one will not be committing the unpardonable sin. Repentance is necessary for salvation to occur and those whose hearts are so hardened as to commit the unpardonable sin will not be doing that.
While not accepting Christ IS a one-way ticket to Hell, the unpardonable sin is apart from that because it’s the act of someone who has totally given themselves over to evil and blasphemy. (Blasphemy of the Holy Spirit such as described in this verse is not using the Lord’s name in vain, or any other manner of blasphemy, which Christ makes clear in that verse. It’s a particular kind which is only committed by those who will not be coming to Christ at any point - and this act is indicative of an attitude and heart and mind-set which are wholly given over to evil.)
Wanted to add that Christ makes it clear in the verse that this sin is not pardonable and will not be. Ergo, it is not something the believer, or those whose hearts are still malleable enough for the Gospel to penetrate, will be committing. It’s not ordinary (assuming there is such a thing, but Christ again draws the differences in this verse, so there must be different types) blasphemy we are talking about here. It’s clear it will not be pardoned, but since repentance is required for salvation and those who commit this sin are beyond that (and yes, there are those who place themselves beyond repentance and have hardened their hearts to such a point that the Holy Spirit ceases to strive with them — O’Hare comes to mind). Christ is warning the unbelievers He is addressing here to go no further down the path they have chosen. (One wonders if they listened and came to Him later. We can only hope.)