Take first this with regard only to what you may recall from your secular schooling in science. Darkness is the absence of light. A windowless closet without a connected light bulb or a flashlight or a candle is black darkness. Light itself is something measurable. When no light is present we call it darkness, period.
Take this now on a spiritual level. How did man come to Life?
"And the LORD God formed man of the dust of the ground, and breathed into his nostrils the breath of life; and man became a living soul." Gen 2:7
And to death?
"And the LORD God commanded the man, saying, Of every tree of the garden thou mayest freely eat:
But of the tree of the knowledge of good and evil, thou shalt not eat of it: for in the day that thou eatest thereof thou shalt surely die." Gen 2:16-17
"And when the woman saw that the tree was good for food, and that it was pleasant to the eyes, and a tree to be desired to make one wise, she took of the fruit thereof, and did eat, and gave also unto her husband with her; and he did eat." Gen 3:6
And so they were "dead" to God as were their offspring until Jesus brought Life anew for mankind.
Is not Light Life and darkness death? I won't go into the scriptures which show that... but remember that Jesus is the Light of the world and he is also Life.
Don't forget that we were all effectively in the eyes of God born dead. We were zombies until we encountered the Life which Jesus is. Those without Jesus remain zombies [walking dead people].
God did not create the evil or the darkness. Rather He created man with possibility within himself to reject the Life and the Light which God was. Man did so. In the darkness man strived to use the "very good" things which God made [Gen 1:31] alone, without Light, without direction [Jerem 10:23] and the results have spiraled downward. Jesus made no difference to men who never acknowledged Him and who never obeyed Him. They remained the darkness of death without Light and without Life. Among them perhaps some became what men call their Hitlers and their Stalins as if those were worse dead men that the rest who also continued their walk in death and darkness. There may be levels of death and darkness but ultimately what can they matter to the dead?
This comes back to the required vision, Helen! Without vision His people perish [Prov 29:18]. Everyone is already dead, so why does anyone worry about guilt and punishment... unless a person has really received Life and rejected it?
Remember also Helen that I would be what some people call an annihilationist. There is no after life for the dead. They simply remain dead. The semblance of life they for an allotted time in this hunk of flesh is all they will ever have. In this flesh we have the opportunity because of Jesus to receive Life... but do all take hold of the glimmer of hope for a real King [Jesus] or do they continuing with children of Israel to choose to have a king like the heathens/gentiles all around them?
Don't however meticulously try to follow every curve in the trail unnecessarily. Simply trust in God and follow Him precisely where he leads you.
We live by faith rather than by knowledge. Sometimes God will give us knowledge of extra things, but as someone has said, we do not have to be theologians of the highest order to walk with Jesus to the end of the road. For this reason I keep coming back to this:
"But seek ye first the kingdom of God, and his righteousness; and all these things shall be added unto you." Matt 6:33