I do not know enough about Buddhist practices to know if there is any room for comparison, but I can say a little something on the practice of lighting candles.
In Protestantism there is a heavy emphasis upon "the word" or "words". Verbal/written forms of communication and expression have a great prominance in various Protestant denominations/ideologies which for all practical puroses tends to shove everything else out of the picture. You see this not only in theory but in practice - Protestant corporate worship is almost entirely verbage (hymn lyrics, spoken prayer whether rote or as is the way of American evangelicals, entirely impromptu.) The same is true with how Protestant traditions impart doctrine - namely, it occurs solely through reading and preaching.
In Orthodox Christiantity however, the entirity of mankind is engaged in the process of spiritual expression/impression. For example, yes there are sermons, but there is also praxis - everything from the architectural layout of the Church ediface, to the choice of tones/sound qualities in liturgical music, through to the Iconography: all of it details the economy of salvation.
The same is also true of prayer. Yes, Orthodox employ "words"; but there is more to a man than his tongue, to give form to what lies in his heart. There are also prostrations, and other bodily acts which speak as eloquently (if not, for many people, more eloquently) as the mouth.
Such would be the case of offering candles or lighting a lamp. No, God does not need the beeswax or the olive oil (and certainly not the light!) - but then again, He does not need our words of praise either. If one wanted to push things really far, one could say we realy don't "need" to pray at all - after all, does not God know what we need better than we do? Does He not know our thoughts better than we do ourselves?
Yet, we are called to pray nonetheless. One could get into all sorts of discussions/arguments as to "why" (in light of God's omniscience), but that's beyond the scope of this posting. Suffice it to say, we need to pray, including for those things which are needed for both the body and the soul.
Lighting a candle is an act of glorification, and indicates perpetuity - an expression of the habitual nature of this prayer in our hearts.
So the candles are words of a different sort. Of course they're not magical items - they will be of no more value than the posturing words of a verbally praying hypocrite if they are lighted carelessly or without any heartfelt devotion.