Gustave Le Bon, here:
A person is not religious solely when he worships a divinity, but when he puts all the resources of his mind, the complete submission of his will, and the whole-souled ardour of fanaticism at the service of a cause or an individual who becomes the goal and guide of his thoughts and actions. Intolerance and fanaticism are the necessary accompaniments of the religious sentiment. They are inevitably displayed by those who believe themselves in the possession of the secret of earthly or eternal happiness. These two characteristics are to be found in all men grouped together when they are inspired by a conviction of any kind. The Jacobins of the Reign of Terror were at bottom as religious as the Catholics of the Inquisition, and their cruel ardour proceeded from the same source.
