Torture people … but don’t kill ….. get them to confess that they are a heretic …… then burn them at the stake alive — (then take their property).
Focus on the women …. they are wives, mothers, daughters ….. that will make the people conform ….Divide up their property…. one third to the inquisitor and catholic bishop … One third to the city …… One third to those who helped capture and convict.
Institute mental conditioning with punishments by God after death for non compliance here on earth.
Have an enemy to hate (Jews).
Make the people dumb by burning the libraries.
Kill other nations if they don’t believe in the fable (Crusades).
Punish anyone that contradicts their stories.