Blasphemy

is,
'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