And God said: ""Let there be light.""
And there was light.

These words mark the first step in the creation of all life. The very genesis of light is tied to the nature and purpose of God--God as the author of light, as the pouring out of light, as light itself.

Believers in the three Abrahamic faiths have always understood God as light. The Hebrew scriptures celebrate this divine illumination: ""Yahweh is my light and my salvation . . ."" (Psalm 27). Christians, too, proclaim that ""God is light, and in him is no darkness at all"" (1 John 1.5). For Muslims, ""Allah is the Light of the...