How did religious pluralism challenge the concept of a unified Europe? (One paragraph with evidence)

Religious pluralism challenged the concept of a unified Europe ... To re-establish order after a period of religious warfare, France introduced limited toleration of the minority Calvinists within a Catholic kingdom (Edict of Nantes, 1598; revoked in 1685). Jews remained a marginalized minority wherever they lived.

The Reformation led to the European wars of religion.

Explanation:

Before the Protestant Reformation, most of western Europe was Roman Catholic. While Europe was vastly diverse at the time, a shared religion and a shared lingua franca (Latin) created a sense of unity among Catholic Europe. The several Crusades launched to recover Holy Land were a Pan-European effort. The Protestant Reformation led to a split in Europe among sharp religious lines, which grew more deeper as more Protestant denominations rejected the Pope's authority. The Reformation led to what have been called the European wars of religion between the 16th and 17th centuries. The Thirty Years' War, fought between 1618 and 1648, was one of the deadliest conflicts in history. Fought across battlefields in most of Europe, it ended with the Peace of Westphalia, which introduced the concept of state sovereignity, marking the beginning of separate nation-states.