Both internally and externally, light manifests in different intensities. Both the sun and the firefly give light. Both the moon and the gem give light. But they are lights of different intensities. Just as external light is of different intensities, so is the light in the mind. A little light helps one to cognize but not to understand. More and more light gives one deeper and deeper understanding. And based on that understanding, we guide ourselves.
A small amount of light merely makes us aware of the encircling darkness. The firefly lights up a tiny sphere, but reveals the vastness of the darkness around it. The Isha Upanishad states that while ignorance puts us in darkness, a little knowledge puts us in greater darkness, as it were.
Pandit Vidyasagar asked Sri Ramakrishna if God had given different power to different people. Sri Ramakrishna was amazed at his naivety. Though it is spiritual light that manifests as perceived light, the two are incomparable, both qualitatively and quantitatively. Sri Ramakrishna says, ‘One ray of light from the Goddess of Wisdom stuns a thousand scholars’. Again, he says, ‘Getting a ray of light from the goddess of learning, a man becomes so powerful that before him big scholars seem mere earthworms.’