Martin Luther was excommunicated becuase he was going against the Roman Catholic church. He was saying that you didn't need to pay indulgences to the Roman Catholic church just to get into heaven. All you had to do was believe that Jesus christ died on the cross to save our sins. So when he went against the Roman Catholic church, the pope was mad becuase if people started believing him, they would lose money.
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Marthin Luther posted his famous “Ninety-Five Theses,” in the Church of Wittemberg, the Ninety-Five Theses, was a declaration of teological debates that sought changes and challenged practices like payments of indulgences. People often payed in order for their family members to go out of purgatory. This enraged Pope Leo X , who saw his personal interests damaged. He refused to retract to his view on the “Ninety-Five Theses,”
Explanation:
Pope Leo X excommunicated him , declaring him an heretic of Catholic beliefs. He issued the papal document called the "Decet Romanum Pontificem. When the revolutionary ideas of Luther began to spread in Europe, the weight of the Catholic Church was decreasing and they soon would solve to the Counter-Reformation , which basically is the reaction to the major social and economic changes that resulted from the ideas of Luther.
