A candle for Tianhou, the Mother of Heaven, and Goddess of the Sea, from a temple in Shenzhen China. While the following information is related to Buddhism, and Tianhou is part of the Taoist pantheon, the symbolism is probably the same:
Candles are a traditional part of Buddhist ritual observances. Along with incense and flowers, candles (or some other type of light source, such as butter lamps) are placed before Buddhist shrines or images of the Buddha as a show of respect. They may also be accompanied by offerings of food and drink. The light of the candles is described as representing the light of the Buddha’s teachings, echoing the metaphor of light used in various Buddhist scriptures.