They didn't have a choice either you were the religion that they wanted you t be or you were held as prisoner ,executed ,or tortured till you died. the Spanish inquisition was started by king Ferdinand and queen Isabella they wanted to make sure that no other religion was being practiced besides Christianity. if you were accused of heresy (the practice of another religion) you were sentenced to die. more than two thirds of the population was killed during either the Spanish inquisition or the Portuguese inquisitions.
The Inquisition was controlled by the Roman Catholic Church- there was both a Roman Inquisition, and a Spanish Variant.
To get them to confess to heresy
To get them to confess to heresy
King Ferdinand was the king during the Spanish Inquisition.
being a "heretic" and/or being a "witch"
Christianity.
The Inquisition banned books during the Renaissance, but it abandoned the brutal measures once used in the Middle Ages.
I don't think there are any specific "lessons" to be learnt from the Inquisition.
books
The Catholic religion.
During the inquisition, most notably the Spanish Inquisition, people who were not Christians (Jews and Muslims) had to convert under the penalty of death. Many were also expelled from Spain and other countries. There was no tolerance in that regard.
They were either converted or slain.