The Parable of the Light of Allah (swt)

God is the Light of the heavens and the earth. The parable of His light is, as it were, that of a niche containing a lamp; the lamp is [enclosed] in glass, the glass [shining] like a radiant star: [a lamp] lit from a blessed tree - an olive-tree that is neither of the east nor of the west the oil whereof [is so bright that it] would well-nigh give light even though fire had not touched it: light upon light! God guides unto His light him that wills [to be guided]; and [to this end] God propounds parables unto men, since God [alone] has full knowledge of all things.

[Qur'an: Surah Nur: 35]