Why and how did the Catholic Church fight its opponents?

Throughout the Middle Ages, the church and religion played a dominant role in the life of society. All human actions were subject to the requirements of the Catholic Church. People were required to pay tithing. The church preached poverty and worship of religion, and the monks and popes lived in luxury. Any manifestation of disobedience by the church was severely punished. A person was excommunicated, which meant the death of the soul. The Inquisition was created, which for a long time perpetrated reprisals against the enemies of the church. The popes sought to keep in subjection not only people, but entire states.