HBSMN:
"If all sin against the Son were also against the Holy Spirit, then the above verse would be a lie. Jesus said when one sins against Him, it shall be forgiven. Sins against the Son are different than sins against the Holy Spirit."
GE:
What about the infinite number of Scriptures that say Christ's blood pays for every and all (my) sin?
"No one can say Jesus is Lord but by the Holy Spirit" is the Word of the God who cannot lie. Therefore to "say a word against" the Son is to "say a word against the Holy Spirit" --- "the Spirit of Christ"!
WHAT ABOUT THE WORTH AND POWER OF JESUS' SACRIFICE AND RESURRECTION? Were it less than what it is, I would not be saved, because I have committed every conceivable and inconceivable sin against the Holy Spirit of God. Then Jesus' own words, "Your sins are forgiven", would be meaningless to me and for me, and the faith God had given me, bluff.
What sin you, and I, have committed was not against the Holy Spirit, what word you, and I, have spoken against God that it is not so bad as not to be blaspheming against the Holy Spirit?
If one takes the word for "but" to say something like 'indeed' in this text, it equalises rather than contrasts sin against the Son and sin against the Spirit.
There simply is no such thing as sin that is less than blasphemy -- for which one might be pardoned, but for the other, not. And there is no such thing as sin that is not sinning against the Holy Spirit. The words, "word spoken" mean 'sin committed', or, and, 'blasphemy spoken against'.