Why is the posting of the 95 Theses by Martin Luther considered a turning point in history?

The posting of Martin Luther's 95 Theses in 1517 is considered a turning point in history because it sparked the Protestant Reformation, challenging the authority of the Catholic Church and its practices, particularly the sale of indulgences. This act of defiance encouraged individuals to question religious dogma and seek personal interpretations of scripture, leading to the emergence of various Protestant denominations. Moreover, it set in motion significant social, political, and cultural changes in Europe, ultimately contributing to the decline of the Church's influence and the rise of secular governance.