Festival of the Supreme Being
Also called: Cult of the Supreme Being, Cult of Reason
Robespierre replaced the atheistic Cult of Reason with a state festival honouring the Supreme Being and the immortality of the soul, staged by David.

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During the Terror churches were closed and a fierce dechristianisation campaign held a “Festival of Reason” in Notre-Dame. Believing atheism corrupted morality, Robespierre had the Convention recognise the Supreme Being and the immortality of the soul in May 1794.
On 8 June 1794 (20 Prairial Year II) Paris held a festival staged by David. Robespierre, as president of the Convention, set fire to an effigy of Atheism in the Tuileries Garden, and the procession moved to an artificial mountain on the Champ de Mars. When the Law of 22 Prairial sped up executions two days later, suspicion and fear spread among fellow deputies that he meant to make himself the high priest of a new creed.