It is a symbol of unity with the other participants and adds a spiritual beauty.

Well it is a CANDLELIGHT vigil, so you do need candles.
It’s to show respect and reverence to the person being honored. Prayers do not go up faster if you are holding a candle.

What’s the point to anything?

It focuses the the energy of your intentions on the physical burning candle, where it (and so, your intentions) can also be noticed and supported by others who notice it.

Metaphorically, it casts a light unto the darkness.

Both Judaism and Christianity seem to use candles for prayer and for other rituals, probably other religions also, so it is something that feels familiar and within cultural norms and expectations. I think people like to feel like they are doing something, and part of a greater group, it helps them feel in control. Rituals do that for people.

What I noticed was the Catholic church and Jewish synagogues sell candles ($$$). I also noticed one time when I was in a church that you could light a candle and were expected to make a donation when you did. Maybe initially it was just practical, because there was no electricity a few thousand years ago, and anything done during the evening, or even indoors where there was little light entering the area, people relied on oil or wax for lighting the area.

So, I think the custom was partly for practical reasons, and also possibly was developed to make money. I hope no one in hot drought areas are lighting candles outside. battery candles sound good.

Moreover, people use verbiage like the soul being like a light or the light of God, and so there is symbolism there.

That’s my guess anyway.

I think @JLeslie is onto something with the practicality angle. Electricity is a relatively new thing in religious services. I wouldn’t be surprised if these traditions date back many centuries or even millennia, but that’s just a guess.

Could it mean the same thing if everyone brought a flashlight instead of a candle??

I pastored a church in Alabama in the late 1990s and early 2000s.

Some do-gooder thought the candles were a fire hazard, so we switched to electric candles (briefly), in the year 2001.

It was so stupid to have the acolytes, who were preteen children, come forward at the
beginning of the of the service, to walk down the aisle in their robes as the introit was playing, and click those electric candles on.

The Christmas service (which aroused someone’s phony fear enough to make us ditch the candles for 2000) would have been a bummer, too—if those battery candles with those firelfy-looking yellowish flickering/blinking battery candles were what we were to have used.

It took the horror of 9/11 (2001) to make us put aside the silliness of electric candles and go back to an actual candle light vigil, which I bought the candles and put together myself, for people to realize, well, what others have said above—that prayer, spirituality, and unity/oneness are only represented well by actual candles against the darkness.

The darkness around us can only draw emphasis to the light.

Unless a live fire or actual candle flames truly are a fire hazard (as in unsupervised or in a dry, arid place that could be set ablaze) would I ever suggest artificial candles as an alternative. Even they, symbolically, are better than no candles at all.

@Yellowdog Do you have any insight into how far back in history candlelight vigils were held?

No—just that churches have been using candles for the sacredness of wax inasmuch as the symbolism of light. Candlemas, that is the same day as groundhog day (February 2nd) was the day candles were cast to first be used for the Pascal/Easter service (March or April) and all subsequent vigils of the following year,

Not sure when that practice started, some time in the middle ages—but before that, oil of course was used for prayer vigils, as many places of worship still use oil.

One uses candles in a menorah, but they represent the oil that was used to rededicate the Temple in Jerusalem after it was defiled.

Yeah, but the eternal flame in the temple is another example of a flame being used in a religious setting.

That’s the Chanukah menorah that represents the oil lasting 8 days, but also there are menorahs with 7 candles.

Jewish people also have the Kaddish candle (there is another name for it) when someone dies.