Here are a few examples of crimes for which people were burnt at the stake by the Spanish Inquisition:

– In about 1530 – Alonca de Vargas, for having smiled at a mention of the Virgin Mary.

…

– Goncales Ruis, for saying to an opponent in a card game: ‘You couldn’t win this game even if you had God as a partner.’

– In 1635 – Pedro Ginesta of Barcelona, at the age of eighty, for having forgotten what day of the week it was and eaten bacon on a Friday.

…

The reason why the Inquisition burnt its victims (or, as was sometimes the case, strangled them – or both) was to ensure that there would be no shedding of blood. The Church wished to observe the principle ‘Ecclesia non novit sanguinem’ (the church is untainted with blood)

from Peter Bowler “The True Believers: Oddities and curiosities of religious faith” (Methuen; Sydney:1986) pp. 157-158