Question: does the bible say there is an unforgivable sin

Answer: Yes, In Christian hamartiology, eternal sins, unforgivable sins, or unpardonable sins are sins which will not be forgiven by God. One eternal or unforgivable sin (blasphemy against the Holy Spirit) is specified in several passages of the Synoptic Gospels, including Mark 3:28-29, Matthew 12:31-32, and Luke 12:10.