Not only on Chanukah is light part of Jewish observance. Frequently, especially on Shabbat and festivals, joy and light go together; the Megillah says, “The Jews had light, joy and gladness” (Esther 8:16).
We honour a deceased person by kindling a light, since “the spirit of man is the light of the Lord” (Prov. 20:27). An eternal light (ner tamid) burns in the synagogue, since “The Lord is my light and my salvation” (Psalm 27:1). Light is a synonym for Torah: “the commandment is a lamp; the Torah is a light” (Prov. 6:23). Without light we would be unable to see each other or the path on which to walk.
However, the Divine creation of light was too overwhelming for the world. The light was so powerful that it “shattered the vessels”, and man’s task is to try to reclaim the sparks. When Rabbi Chiyya and Rabbi Shimon saw the dawn breaking on the horizon, Rabbi Chiyya said, “So too is Israel’s redemption; at first it will only be slightly visible, then it will shine forth more brightly, and finally it will break forth in all its glory” (Shir HaShirim Rabba 6:10).
The Zohar, the great work of Kabbalah, likewise asserts that “the light of the Messiah” will gradually illumine the world and then break forth in its full glory.