What is Holy Ghost?
The Holy Ghost is a member of the Godhead, along with God the Father and His Son, Jesus Christ.
The  Holy Ghost is sent from the Father ( John 15:26 ) to man in the name of the Father, or the Son (John 14:26 ) .In the name of mean with the authority to represent someone, so Holy Ghost may represent the Father and the Son. He has the influence of teaching and reminding the words of the Father or the Son. He act on the spirit of man, not person to person. He shall not speak of himself; but whatsoever he shall hear, that shall he speak: and he will show things to come( John 16:13 )

SINS AGAINST THE HOLY GHOST
The sin or blasphemy against the Holy Ghost is mentioned in Matthew 12:22-32; Mark 3:22-30; Luke 12:10 (cf. 11:14-23); and Christ everywhere declares that it shall not be pardoned. No one can commit this sin unless Holy Ghost has ever been sent to him from the Father  as he has to deny the Holy Ghost sent to him for his own reason.











John 14:26 But the Comforter, which is the Holy Ghost, whom the Father will send in my name, he shall teach you all things, and bring all things to your remembrance, whatsoever I have said unto you.
John 15:26 But when the Comforter is come, whom I will send unto you from the Father, even the Spirit of truth, which proceedeth from the Father, he shall testify of me:
John 16:13 Howbeit when he, the Spirit of truth, is come, he will guide you into all truth: for he shall not speak of himself; but whatsoever he shall hear, that shall he speak: and he will shew you things to come