Christ now warns of the unpardonable sin—the blasphemy against the Holy Spirit. This is not every doubt or blasphemous word, but a specific and settled rejection of God’s truth when it has been made known through the Spirit’s clear testimony. When a man, with full knowledge, calls the Spirit’s work demonic, he reveals a heart that is not only hostile to God but irreversibly seared. *Let us take this not as a point of speculative terror, but as a sober warning. If we are grieved by this sin and fear we may have committed it, that very grief is evidence that we have not, for the heart that has sinned in such a manner is no longer tender.
