Before addressing the use of votive candles in particular, we have to appreciate the symbolism of light and the general usage of candles in religious practice. In Judaism, a perpetual light was kept burning in the Temple and the synagogues not only to insure the ability to light other candles or oil lamps in the evening but also to show the presence of God (cf. Exodus 27:20-21 and Leviticus 24:2-4). Later, the Talmud prescribed a lit lamp at the Ark, where the Torah and other writings of Sacred Scripture were kept, to show reverence to the Word of God. (This practice probably influenced our own one of having a lit candle near the Tabernacle to indicate the presence of and to show reverence for the Blessed Sacrament.)
Roman pagan culture also used candles in religious practice. Lit candles were used in religious and military processions, showing the divine presence, aid, or favor of the gods. With the development of emperor worship, candles were also lit near his image as a sign of respect and reverence. Remember that by the time of Jesus, the emperor was considered divine and even given the titles, Pontifex Maximus(High Priest) and Dominus et Deus (Lord and God).
Christians adapted the use of lit candles (and oil lamps in the Eastern Roman Empire) for Mass, liturgical processions, evening prayer ceremonies, funeral processions, and, again, to show reverence to the reserved Blessed Sacrament. Moreover, there is evidence that lit candles or oil lamps were burned at the tombs of saints, particularly martyrs, by the 200s, and before sacred images and relics by the 300s. St. Jerome (d. 420) in his Contra Vigilantium attested to this practice. Note, however, that this practice probably existed well before our available written evidence.
In our Catholic tradition, in early times as well as today, light has a special significance– Christ. Recall Jesus said, “I am the light of the world. No follower of mine shall ever walk in darkness; no, he shall possess the light of life" (John 8:12) and “I have come to the world as its light, to keep anyone who believes in me from remaining in the dark" (John 12:46). Moreover, the Prologue of St. John’s Gospel connects Christ and true life with the imagery of light: “Whatever came to be in Him, found life, life for the light of men" and “The real light which gives light to every man was coming into the world" (John 1:4, 9). For this reason, in our liturgy for the Sacrament of Baptism, the priest presents a candle lit from the Paschal candle, which in turn symbolizes the Paschal mystery, and says to the newly baptized, “You have been enlightened by Christ. Walk always as children of the light and keep the flame of faith alive in your hearts. When the Lord comes, may you go out to meet Him with all the saints in the heavenly kingdom" (Rite of Christian Initiation of Adults). The light then is a symbol of faith, truth, wisdom, virtue, grace, the divine life, charity, the ardor of prayer, and the sacred presence which flow from Christ Himself.
With this background, we can appreciate the usage of votive candles. Here, as in early Christian times, we light a candle before a statue or sacred image of our Lord or of a saint. Of course, we do not honor the statue or the image itself, but whom that statue or image represents. 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 light also shows a special reverence and our desire to remain present to the Lord in prayer even though we may depart and go about our daily business.
Interestingly, in the Middle Ages, the symbolism of the votive candles was elaborated. St. Radegund (d. 587) described a practice whereby a person would light a candle or several candles which equaled his own height; this was called “measuring to" such a saint. Although it may seem peculiar to us, this “measuring" actually reflects the idea of the candle representing the person in faith who has come intothe light to offer his prayer.
Also, some Medieval spiritual writers expanded the imagery of the candle itself: beeswax symbolized the purity of Christ; the wick, the human soul of Christ; and the light, His divinity. Also, the burning candle symbolized a sacrifice, which is made in both the offering of the prayer and the acceptance of the Lord’s will.
In all, the usage of votive candles is a pious practice which continues today in many Churches. The symbolism does remind us that prayer is a “coming into" the light of Christ, allowing our souls to be filled with His light, and letting that light burn on in our souls even though we may return to other activities.