The primary goal of Martin Luther during the Reformation was to reform the practices and beliefs of the Catholic Church, primarily addressing issues he believed were corrupt, such as the sale of indulgences. His 95 Theses, posted in 1517, criticized these practices and called for a return to Biblical truths. Luther emphasized salvation through faith alone, the authority of the Scriptures, and the priesthood of all believers, challenging the church's hierarchical structure. His actions ignited widespread debate, leading to the establishment of Protestant denominations and fundamentally changing the religious landscape in Europe and beyond.