William G. T. Shedd,
Sermons to the Natural Man
“ The sin against the Holy Ghost is unpardonable, not because there is a grade of guilt in it too scarlet to be washed white by Christ's blood of atonement but, because it implies a total quenching of that operation of the third Person of the Trinity which is the only power adequate to the extirpation of sin from the human soul. The sin against the Holy Ghost is tantamount, therefore, to everlasting sin. ”
