The "95 Theses" is a document written by Martin Luther in 1517, which criticized the practices of the Catholic Church, particularly the sale of indulgences. Luther argued that salvation could not be bought and emphasized the importance of faith and scripture in Christianity. His theses sparked widespread debate and are often credited with initiating the Protestant Reformation. Luther posted the theses on the door of the Castle Church in Wittenberg, Germany, making them accessible to the public. This act encouraged others to question the Church's authority and practices, leading to significant religious and social changes in Europe. The "95 Theses" remain a foundational text in Christian history.