The candle is a very powerful symbol in human consciousness. There is something about that tiny point of light, flickering, existing and resisting a world that is dark and empty, which speaks to the deepest part of the human soul. This is one of the reasons that candles have such a profound significance in so many disparate religions throughout the world.
The candle is a powerful symbol in Judaism, and one is lit every Friday night to celebrate the beginning of the weekly Sabbath. On Saturday evening, a Havdalah candle is lit to mark the end of the Sabbath. Candles are also used in the Chanukah ceremony, where a candle is lit every evening for eight nights, to commemorate the candle which miraculously burned for eight days, when the Jews recovered their temple from the Greek / Persian Invaders. For the Jewish people, the candles flame represents the ever burning flame of the divine being.
In Judaism a candle is also used to commemorate those who have passed away, and they are often lit to commemorate a loved one, or those who died tragically, such as in the holocaust.
In Christianity the candle is used for both religious and decorative purposes. In its decorative function, it is a representation of the Creators light, or specifically the light of Jesus. For this reason you will often find a candle lit and placed on an alter. Ritually, candles are often lit and placed in front of pictures of icons in the orthodox tradition. A votive candle may also be lit to accompany prayer. Some churches also use a Paschal candle which represents Jesus, and is only lit on Easter and other very special occasions.
In Buddhism, candles are often placed in front of statues of the Buddha along with food or drink as a sign of respect. Symbolically they represent the light of the Buddha's teaching and the enlightenment they added to the world.
In the Hindu tradition a diya, or clay lamp, is a very important part of any religious ritual. The lamp holds the candle during the ceremony, and acts as a symbol of prosperity and enlightenment. Every year they also celebrate Diwalli which is also known as the festival of light. On this holiday lamps are lit to symbolize life and hope and the conquest of good over evil.
The symbolic nature of a candle gives it significance in many of the world's major religions. Whether it symbolizes the supreme creator, or the hope of mankind, its flickering light is an inspiration to many who behold its glow.