What arguments did Martin Luther make against indulgences in 95 theses?

In his 95 Theses, Martin Luther argued that indulgences undermined the true essence of repentance and salvation, which he believed should come from genuine faith and remorse rather than monetary transactions. He contended that the selling of indulgences exploited the faithful, leading them to believe they could buy their way into heaven. Luther emphasized that only God, not the Church, had the authority to grant forgiveness, asserting that salvation was a gift of grace rather than a commodity. His theses sparked widespread debate and ultimately contributed to the Reformation movement.