This verse scares the crap out of some folks. They are not sure what it means but have been told by Christianity that it is unpardonable SIN, and anyone who commits it can’t be saved and will be tortured in hell forever.
But here is what the above verse means to me in a nutshell:
1. The "Holy Spirit" is the "spirit of truth" (John 16:3)
2. “No one can say, 'Jesus is Lord', except by the Holy Spirit “
(1 Corinthians 12:3)
3. Christ Jesus is "the Savior of the world” (John 4:42).
4. "...when He, the Spirit of truth, comes, He will guide you into all the truth..." (John 16:3)
Failing to believe the "truth" about Christ Jesus as revealed by the "Holy Spirit" is never forgiven anyone (Jew, Gentile or Christians) in this age or the next - it is blasphemy of spirit! However, in the next age ALL HUMANS will know the truth and confess Jesus Christ is Lord to the glory of God.