In the beginning, we learn preliminary concentration practices. These are not meditation. We learn to focus on a candle, to focus on our heart, to focus on the breath, to watch an object, to stare at an image or a statue, to meditate on a mantra. Or gradually we may work doing visualizations as a concentration practice. These come in stages relative to how concentrated we become. All of these things are preliminary, none of them are meditation; they are just concentration practices. So the essence of what we are working on in the beginning is only that: to learn how to concentrate. - "Concentration", Gnostic Meditation

Candles are not necessary for meditation. However, some people may find them helpful.