The Cult of the Supreme Being was a state-sponsored form of deism introduced during the French Revolution. Instated by Maximilien Robespierre (a leading figure of the Reign of Terror and a prominent member of the Committee of Public Safety) on 7 May 1794, this religious doctrine emerged during a period of radical dechristianization. The cult aspired to replace Roman Catholicism and to establish a new moral and civic ideology. This new religious philosophy was rooted in the belief in a Supreme Being and the immortality of the soul. The rationale behind it involved a deep conviction in moral and ethical principles, which were seen as essential for societal cohesion. The National Convention officially endorsed this religion, demonstrating how deeply entangled religion and politics had become during the Revolution. In conjunction with the establishment of the Cult of the Supreme Being, a grand fete was organized. Held on 8 June 1794 (20 Prairial Year II in the French Republican Calendar) in Paris, the festival was orchestrated to reinforce the new religious tenets. This event featured a ceremony on the Field of Mars (Champ de Mars), where a colossal paper-mâché mountain was erected. Robespierre descended from this artifice, symbolizing the descent of the Specter of Virtue among the people. Speeches, music, and processions filled the day, intending to foster unity among the citizenry and adherence to the new cult. Despite these efforts, the Cult of the Supreme Being faced criticism and opposition. Many perceived it as a tool for Robespierre to consolidate power. Skepticism abounded among different segments of the population, including atheists, radical revolutionaries, and traditional Catholics. The forced secularization and transformation of religious beliefs alienated substantial portions of society. The demise of Robespierre on 28 July 1794 (10 Thermidor Year II) led to the rapid decline of the Cult of the Supreme Being. His fall from power marked a significant shift in the dynamics of the French Republic, closing the brief chapter of this state-imposed deistic religion. The resurgent influence of the more traditional religious sentiment and the subsequent relaxation of anti-clerical measures underscored the resistance to radical changes imposed upon deeply rooted cultural and spiritual beliefs.