A candle is just a solid block of wax with an embedded wick, which is lit to provide light.
And yet it is much more than that.
To the Buddhist they are part of ritual observance. 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.
In Christianity the candle is commonly used in worship both for decoration and ambiance, and as a symbol that represents the light of God or, specifically, the light of Christ. The altar candle is often placed on the altar, usually in pairs. Candles are also carried in processions, especially to either side of the processional cross. A votive candle or taper may be lit as an accompaniment to prayer.
In Sweden (and other Scandinavian countries), St. Lucia Day is celebrated on December 13 with the crowning of a young girl with a wreath of candles.
In many Western churches, a group of candles arranged in a ring, known as an Advent wreath, are used in church services in the Sundays leading up to Christmas. In households in some Western European countries, a single candle marked with the days of December is gradually burned down, day by day, to mark the passing of the days of Advent; this is called an Advent candle.
In Judaism, a pair of Shabbat candles are lit on Friday evening prior to the start of the weekly Sabbath celebration. On Saturday night, a special candle with several wicks and usually braided is lit for the Havdalah ritual marking the end of the Sabbath and the beginning of the new week.
The eight-day holiday of Hanukkah, also known as the Festival of Lights, is celebrated by lighting a special Hanukkiyah each night to commemorate the rededication of the Temple in Jerusalem.
A memorial candle is lit on the Yahrtzeit, or anniversary of the death of a loved one according to the Hebrew calendar. The candle burns for 24 hours. A memorial candle is also lit on Yom HaShoah, a day of remembrance for all those who perished in the Holocaust.
A seven day memorial candle is lit following the funeral of a spouse, parent, sibling or child.
Candles are also lit prior to the onset of the Three Festivals (Sukkot, Passover and Shavuot) and the eve of Yom Kippur, and Rosh Hashana.
A candle is also used on the night before Passover in a symbolic search for chametz, or leavened bread, which is not eaten on Passover.
Even Secularists have a symbolic use for candles. For some Humanists the candle is used as a symbol of the light of reason or rationality. The Humanist festival of Human Light often features a candle-lighting ceremony.
יְהִי אוֹר - fiat lux - γενηθήτω φῶς – let there be light.
“And God said, Let there be light: and there was light.
And God saw the light, and it was good; and God divided the light from the darkness.”