Fire or flame is a very common spiritual symbol and appears in many forms. The burning bush of Moses, the pillar of fire that led the Jews out of Egypt and the flame of the Sun of Righteousness that will burn up evil in the End Times are just a few examples.
In general, fire or flames symbolize transformation, purification, rebirth and the generative power of the sun. It can also represent strength, power or energy. Fire can symbolize the illuminated or enlightened as in the tongues of fire that appeared over the apostles. The soul leaving the body after death is often depicted as flame. Kindling a fire can symbolize birth or rebirth. Fire and water together represent the active and passive principles. In many Native American cultures, fire, especially in the Medicine Lodge, is considered the dwelling place of the Great Spirit.
Fire is also representative of Hell, devils, demons, and destruction. This apparent contradiction can be easily explained. The fire of enlightenment is a spiritual fire while the destructive fire is material.
Spiritual schools often instruct students to strengthen their energy centers (chakras), by visualizing them as balls of fire or miniature suns in the appropriate color, and to see them getting larger and stronger as you absorb the spiritual light, or fire, of the sun.