The people who walk in darkness will see a great light; Those who live in a dark land, the light will shine on them. (Isaiah 9:2)
The complete absence of light leaves us helpless in absolute darkness. That is true in a spiritual sense as well as in the physical realm. Without the spiritual knowledge, understanding and enlightenment that only comes from God and His word, we are rendered helpless in total spiritual darkness; The light shines in the darkness, and the darkness did not comprehend it.(1 John 1:5)
Tragically, those who die in spiritual darkness, not having seen or accepted God's light, will also spend eternity alone in the utter darkness of hell; Throw out the worthless slave into the outer darkness; in that place there will be weeping and gnashing of teeth.(Matthew 25:30)
Those living in spiritual darkness don't even comprehend the utter darkness because they are spiritually blind; ...in whose case the god of this world (Satan) has blinded the minds of the unbelieving so that they might not see the light of the gospel of the glory of Christ, who is the image of God. (2 Corinthians 4:4)
The great light that shines in the spiritual darkness of our hearts is, of course, Jesus Christ; Then Jesus spoke to them, saying, "I am the Light of the world; he who believes Me will not walk in the darkness, but will have the Light of life."(John 8:12)
May your spiritual eyes be opened to see the marvelous light of the gospel of the glory of Christ! Maranatha!