It is very common to depict god as light. Here is look at the luminous nature of spiritual reality through the teachings of Sri Ramakrishna in Hinduism.
Swami Vivekananda says, ‘We put our hands over our eyes and weep that it is dark. Take the hands away and there is light; the light exists always for us, the self-effulgent nature of the human soul.
Sri Ramakrishna spoke in very clear terms about the luminous nature of spiritual reality. He said – I had the immediate knowledge of the Light that is Mother. … It was as if the houses, doors, temples and all other things vanished altogether; as if there was nothing anywhere! And what I saw was the boundless infinite Conscious Sea of Light! However far and in whatever direction I looked, I found a continuous succession of Effulgent Waves coming forward, raging and storming from all sides with a great speed.
Sri Ramakrishna Paramahamsa described his vision as a ‘luminous sea of Consciousness’. It is interesting to note that when Sri Ramakrishna had that experience, he was not contemplating light. Rather he was contemplating on the form of the Divine Mother. In other instances also, we find that his visions are associated with light. For example, when he had the vision of Sri Chaitanya, he saw him as a radiant youth.
Those that associated with Sri Ramakrishna also had such experiences. Swami Saradananda describes the unusual experience of Hriday, Sri Ramakrishna’s nephew: One night Hriday saw the Master going towards the Panchavati. Thinking that he might require his water pot and towel, he took them and followed him. As he was going, Hriday … saw … that the Panchavati was illumined by the light coming out of [Sri Ramakrishna’s] body. … Taking all this to be an optical illusion, Hriday rubbed his eyes again and again, observed all the surrounding things in their natural state and looked at the Master once more. … He repeatedly saw the Master in that luminous form. Extremely amazed at it, Hriday … looked at his own body and saw that he too was an effulgent being made of light.
Sri Ramakrishna himself says, ‘The more you advance toward God, the less you will see of His glories and grandeur.’ After various visions of names and forms, the aspirant ‘sees only Light without any attributes’. ‘At last he sees the Indivisible Light and merges in It’.
Source – Excerpts from an article titled ‘Lead, Kindly Light by Prof. Vijaya Kumar Murty published in Prabuddha Bharata magazine November 2006 issue.