The sin against the Holy Spirit is not to be regarded simply as an isolated act, but also as the external symptom of a heart so radically and finally set against God that no power which God can consistently use will ever save it. This sin, therefore, can be only the culmination of a long course of self-hardening and self-depraving. He who has committed it must be either profoundly indifferent to his own condition, or actively and bitterly hostile to God- so that anxiety or fear on account of one's condition is evidence that it has not been committed. The sin against the Holy Spirit cannot be forgiven, simply because the soul that has committed it has ceased to be receptive of divine influences, Strong, Augustus H.. Systematic Theology