'Deep Darkness' in the Bible

The people who walked in darkness have seen a great light; for those living in a land of deep darkness, a light has shined upon them.

On that day the deaf will hearthe words of a document,and out of a deep darknessthe eyes of the blind will see.

Who among you fears the Lord? Who obeys his servant? Whoever walks in deep darkness, without light, should trust in the name of the Lord and rely on his God.

"So justice is far from us, and righteousness does not reach us. We wait for light, but look there is darkness; we wait for brightness, but we walk in deep darkness.

For, look, darkness covers the earth and deep darkness covers the nations, but the Lord shines on you; his splendor appears over you.