Examples of using "Ketzerei" in a sentence and their english translations:
She was accused of being a heretic.
Heresy was a crime for which people were sometimes sentenced to death.
Galileo was cleared of charges of heresy, but was told that he should no longer publicly state his belief that Earth moved around the Sun.
In 1632, he published a book that stated, among other things, that the heliocentric theory of Copernicus was correct. Galileo was once again called before the Inquisition and this time was found guilty of heresy.