Francis of Assisi
When Francis returned to Assisi he had a religious conversion experience, including a reported message from Christ calling him to leave this worldly life.  He began taking his Christianity faith seriously.  He acted towards people as if the Gospels were his law, taking Jesus Christ as a literal example for loving one another.  He dressed in rough clothes, ask and begged for his sustenance, and preached purity and peace.  His family disapproved, and his father disinherited him, so Francis renounced his wealth and inheritance. After that Francis started visiting hospitals and caring for the sick including of leprosy.