What are Luther's arguments for why indulgences are bad for Christians?

Luther argued that indulgences undermine the core principles of repentance and faith by promoting the idea that salvation can be purchased rather than earned through genuine contrition and a relationship with God. He believed they exploited the faithful's fear of sin and damnation, encouraging a transactional view of grace that detracted from the true message of the Gospel. Furthermore, Luther contended that indulgences misrepresented God's mercy and love, leading believers away from a sincere pursuit of spiritual growth and true redemption.