Medieval Christians were not tolerant towards:
-other religions, it caused crusades on Middle East and slaugher of Old Prussians and Albigensians, attacks on Lithuanians. Crusades still affect negatively Western World- Middle East relations.
-people who thinked differently, like Galileo, and many nameless invantors, free thinkers, healers. Those who questioned the laws of God (interpreted by Pope) were judged by inquisition.