Matthew 12:31–32. “Blasphemy against the Holy Ghost”
The Prophet Joseph Smith explained how someone commits the sin of blasphemy against the Holy Ghost:
“He must receive the Holy Ghost, have the heavens opened unto him, and know God, and then sin against him. After a man has sinned against the Holy Ghost, there is no repentance for him. He has got to say that the sun does not shine while he sees it; he has got to deny Jesus Christ when the heavens have been opened unto him, and to deny the plan of salvation with his eyes open to the truth of it; and from that time he begins to be an enemy” (in History of the Church, 6:314).
Sometimes students are concerned about the sin of blasphemy against or denying the Holy Ghost. President Spencer W. Kimball taught:
“The sin against the Holy Ghost requires such knowledge that it is manifestly impossible for the rank and file to commit such a sin” (The Miracle of Forgiveness [1969], 123).
Elder James E. Talmage of the Quorum of the Twelve Apostles explained why Jesus was warning the Pharisees of the unpardonable sin in Matthew 12:31–32:
“Jesus was merciful in His assurance that words spoken against Himself as a Man, might be forgiven; but to speak against the authority He possessed, and particularly to ascribe that power and authority to Satan, was very near to blasphemy against the Holy Ghost, for which sin there could be no forgiveness” (Jesus the Christ, 3rd ed. [1916], 269).