The inner light, when it comes, heralds a higher state of consciousness. In time, that light blazes "as a million suns", as it is described in Indian scriptures. Even ordinary people, long before they even see the inner light, use light as a metaphor for any sort of mental awakening.
As sunlight entering the ocean loses power at increasing depths, and finally becomes invisible, so with divine light as it enters human consciousness. Many forms of life that live at great depths produce luminescence of their own, to compensate for the absence of outer light.
Even so, the delusion-darkened ego produces its own version of spiritual awareness by the excitement it generates in its relation to matter.
People's awareness darkens as their awareness becomes denser with matter-identification. This is the way cosmic creation is manifested.
The denser our consciousness, the less spiritual light is able to penetrate mental fog. If we are deeply identified with matter, we find it difficult to think clearly.
People who are completely identified with their bodies consider the senses and sense pleasures the ultimate of existence. Seldom, if ever, do they have an abstract thought. By nature they are reactive, not active in a creative sense. A clear mind is a sign, outwardly, that the inner light also is clear. A dull mind, on the other hand, is a sign that the inner light is dull and unfocused.
The English language contains two meanings for light. The first meaning is the opposite of darkness. The second meaning pertains to lightness of weight.
This coincidence expresses a truth: The more light in our consciousness, the more light-weighted we feel in awareness.
Influences that increase this sense of lightness increase also the mind's receptivity to visible light. Dense, heavy foods, however, cloud the mind and make its consciousness heavy. Too much sleep darkens the mind and results in sluggish thinking.
Alcoholic beverages and consciousness-changing drugs darken the mind, as also too much sensory stimulation and sensual indulgence.
All activity, in fact, that absorbs us in materiality, and that lessens our spiritual awareness, obscures the mind, reducing its clarity.
The spiritual reason for moral living, then, is that it lightens our consciousness, loosens our shackles of ego and matter-consciousness, and attunes us more sensitively to the redeeming inner light.
Diving redemption means withdrawing from identification with delusion, and becoming inwardly absorbed in the light of truth.
When the sky is darkened by clouds, the sunlight grows dim: not because its power is any weaker, but because the intervening vapour obscures it.
Darkness enters our consciousness because of attachment to material grossness. Mental clarity is affected also by clouds of doubt and restlessness, emotion such as fear, anger and hatred. Anything that prevents us from seeing life with dispassion, obscures the inner light.
Paramhansa Yogananda pointed out in Autobiography of a Yogi that samadhi or supreme ecstasy cannot come through mere intellectual willingness or open-mindedness. It comes in time with a natural inevitability to the sincere devotee.
It is steadfast deep devotion rather than passivity or force that enables absorption in the light. Most important is an attitude of loving receptivity towards Christ consciousness or Kuthastha Chaitanya, through that one whom God has ordained as your true, or sat, guru.