This light that Allah grants His servant is the greatest favour He bestows upon him and the foundation of all goodness. However strong this light becomes, it remains created. Beware, then, lest your insight weaken and your discernment and knowledge diminish, leading you to suppose that this is the light of direct vision, through which the heart beholds the light of the Holy Essence. Rather, it is the light of knowledge and faith. Some Sufis are afflicted by this error when powerful inward experiences come upon them, leading them to extravagant utterances and foolish speech incompatible with knowledge and faith.
At the other extreme, someone coarse in nature and hard of heart may be enveloped in accumulated darkness and overtaken by one heedless state after another, leaving him with no share whatsoever of this light. Indeed, through his foolishness and scant inward experience, he may even scorn these spiritual states and have no desire for them. But when Allah blesses a servant with sound knowledge drawn from the Quran and Sunnah, and he gains understanding of Allah’s names and attributes, worships Allah in accordance with them, and strives to attain excellence in worship—worshipping Allah as though he sees Him, and, if he does not see Him, knowing that Allah sees him—and constantly remembers Allah Most High, his heart becomes illuminated. He experiences the greatest delights through the pleasure of knowing Allah and the inward experiences of faith. “That is the bounty of Allah, which He gives to whom He wills, and Allah is the possessor of great bounty”1.
When a believer’s faith becomes complete, Allah illuminates his heart, revealing to him the realities of things and granting him discernment by which he distinguishes truth from falsehood. This light becomes the sustenance of the servant’s life and his source of strength for goodness, both in knowledge and in action. The doubts that intrude upon his knowledge and certainty, and the desires born of heedlessness and darkness, are dispelled. His heart becomes light, his speech becomes light, and his deeds become light, while light surrounds him on every side.
The disbeliever, the hypocrite, the opponent, and the heedless person who turns away—all stumble about in darkness. Each has a share of darkness proportionate to the elements and causes of it within him. Allah alone grants success2.