Which document is considered to have initiated the Protestant Reformation?

The Ninety-Five Theses, written by Martin Luther in 1517, is widely recognized as the catalyst for the Protestant Reformation. This document challenged the practices of the Catholic Church, particularly the sale of indulgences, which Luther viewed as a corrupt way of generating revenue at the expense of believers' faith. By posting these theses on the church door in Wittenberg, Luther ignited widespread debate about church practices and authority, which resonated with many who were discontented with the Church's corruption.

The publication of the Ninety-Five Theses used the relatively new technology of the printing press, allowing Luther's ideas to spread rapidly throughout Europe. This sparked significant theological discussions that led to the formation of various Protestant denominations and a fundamental shift in the religious landscape of the time.

In contrast, the other documents mentioned, like the Council of Trent, the Edict of Nantes, and the Peace of Augsburg, were responses to the Reformation and dealt with issues arising from the conflict such as church reforms and the recognition of different Christian denominations. They did not initiate the movement itself but were rather reactions to the changes and divisions that occurred as a consequence of Luther’s challenges to the Catholic Church.