'Dissing' God (Father, Son, or Holy Ghost); speaking of God with disrespect, a lack of reverence, or in a blaming critical manner; speaking evil of God; speaking evil of others falsely.

Wherefore I say unto you, all manner of sin and blasphemy shall be forgiven unto men: but the blasphemy against the Holy Ghost shall not be forgiven unto men. And whosoever speaketh a word against the Son of Man, it shall be forgiven him: but whosoever speaketh against the Holy Ghost, it shall not be forgiven him,neither in this world, neither in the world to come.
Matthew 12:31 -32