Matthew:
12:31 Wherefore I say unto you, All manner of sin and blasphemy shall be forgiven unto men: but the blasphemy against the Holy Ghost shall not be forgiven unto men.
12:32 And whosoever speaketh a word against the Son of man, it shall be forgiven him: but whosoever speaketh against the Holy Ghost, it shall not be forgiven him, neither in this world, neither in the world to come.
(Words of JC)
Christians cite this as the only example of an unforgivable sin.
Can a Christian please explain how does someone commit "blasphemy against the Holy Ghost"?
I invite as many views as possible.