I learned a while back, that lighting a candle during prayer, or anytime for that matter, lets Spirit know that it is welcomed in a place or space.

Fire symbolizes many things, including passion, desire, resurrection, eternity, destruction, rebirth, hope, hell, and purification.

Candle Color Meanings:

Red - Passion, Strength, Career, Lust, Action, Independence, Survival

Brown - House Blessing, Earth, Pets/Animals, Stability, Locating Lost Items

White - Purity, Divination, Peace, Healing, Exorcism, Innocence

Black - Safety, Protection, Banishing Negative Energy, Shapeshifting

Orange - Creativity, Justice/Legal Matters, Opportunity, Celebration, Ambition