What is Martin Luther's objection to the papal indulgence?

Martin Luther's primary objection to papal indulgences was that they undermined the core Christian belief in salvation through faith alone, rather than through financial contributions or works. He argued that the sale of indulgences exploited the faithful and distorted the true purpose of repentance and forgiveness. Luther believed that the Church should not have the authority to grant absolution for sins in exchange for money, as it compromised the integrity of the Gospel and the relationship between individuals and God. His objections were famously articulated in his Ninety-Five Theses, which sparked the Protestant Reformation.