'Darkness' in the Bible

The sun will be changed to darkness and the moon to blood before the great and glorious day of the Lord comes.

Now look, the hand of the Lord is against you, and you will be blind, unable to see the sun for a time!" Immediately mistiness and darkness came over him, and he went around seeking people to lead him by the hand.

to open their eyes so that they turn from darkness to light and from the power of Satan to God, so that they may receive forgiveness of sins and a share among those who are sanctified by faith in me.'