“I am the light of the world;
he who follows me will not walk in darkness,
but will have the light of life.” -John 8:12
You may have seen vigil candles when entering a church. With these, the  “light signifies our prayer offered in faith coming into the light of God. With the light of faith, we petition our Lord in prayer, or petition the saint to pray with us and for us to the Lord.” The word “vigil” comes from the Latin vigilia and refers to keeping watch.
The vigil candle that is lit remains so for a period of time (either a certain number of hours or a few days) and symbolize how the person desires “to remain present to the Lord in prayer even though we may depart and go about our daily business.” It also reminds the individual how the saint is constantly praying for their petitions.
Another word for these candles is a “votive” candle and comes from the Latin votum, meaning promise, dedication or simply “prayer.” 

Vigil Candle Offering