The original idea of the Shabbat Candles was lighting the Shabbat's evening dinner. Lightning in both ways - physically and spiritually. Some times I think that the material reason in not relevant anymore. Everyone has lights in their houses, so why the candles?

Until the last Shabbat. The lights went out in the middle of the evening's dinner. My wife was mad at me because I adjusted the Shabbat clock to shut down the light too early. The candles saved our dinner (and my skin...).
So maybe the candles are not so irrelevant after all.