Fire (Living). A figure of speech to denote deity, the “One” life. A theurgic term, used later by the Rosicrucians. The symbol of the living fire is the sun, certain of whose rays develope the fire of life in a diseased body, impart the knowledge of the future to the sluggish mind, and stimulate to active function a certain psychic and generally dormant faculty in man. The meaning is very occult.
Source: H.P.Blavatsky - The Theosophical Glossary