On this day we celebrate the Feast of the Presentation of the Lord, the Purification of the Virgin Mary, Candlemas.
"Why do we in this feast carry candles? Because the Gentiles dedicated the month of February to the infernal gods, and as at the beginning of it Pluto stole Proserpine, and her mother Ceres sought her in the night with lighted candles, so they, at the beginning of this month, walked about the city with lighted candles. Because the holy fathers could not extirpate this custom, they ordained that Christians should carry about candles in honor of the Blessed Virgin; and thus what was done before to the honor of Ceres is now done to the honor of the Virgin."
--from a Sermon of Pope Innocent XII, quoted in Curiosities of Popular Customs and of Rites, Ceremonies, Observances, and Miscellaneous Antiquities, by William S. Walsh, J. B. Lippincott Company, Philadelphia, 1897.