What is the unforgivable sin?A Scripture-grounded answer about what is the unforgivable sin

The unforgivable sin — blasphemy against the Holy Spirit — is described by Jesus in Matthew 12:31-32 and Mark 3:29. In context, the Pharisees attributed the work of the Holy Spirit (Jesus casting out demons) to Satan. Most theologians understand this as a persistent, willful rejection of the Spirit's testimony about Christ — a hardened refusal to acknowledge God's work even while seeing it clearly. The very fact that someone worries about having committed this sin is generally considered evidence that they have not, since genuine blasphemy against the Spirit involves a callous indifference, not anxious concern.