The Bible reveals that "God is light, and in him is no darkness at all" (1 John 1:5), and also that, in the ages to come, there will be no more darkness. God promises twice that there shall be "no night there" (Revelation 21:25; 22:5), in the very last references to night in the Bible.
Why, then, is there darkness, and where did it come from? God gives the answer: "I am the Lord, and there is none else. I form the light, and create darkness" (Isaiah 45:6-7). Light was always in and with God, but the darkness had to be created! And, it has a purpose, serving as a contrast to the light.
Men and women were created to love and have fellowship with their Creator, not as robots but in freedom. Darkness thus served as the choice that could be made against God and the light, for those so minded. Satan and his hosts of fallen angels and wicked spirits have become "the rulers of the darkness of this world" (Ephesians 6:12). The tragedy is that ever since Adam, men have "loved darkness rather than light, because their deeds were evil" (John 3:19), and so have been practicing "the works of darkness" (Romans 13:12), and deserving nothing but "the blackness of darkness for ever" (Jude 13).
But our Creator has become our Redeemer. He "hath called you out of darkness into his marvellous light" (1 Peter 2:9), paying the great price for our redemption on the cross. The Father "hath delivered us from the power of darkness, and hath translated us into the kingdom of his dear Son" (Colossians 1:13); we are now free to enter into the eternal fellowship with God that He had planned before the world began. We should "have no fellowship with the unfruitful works of darkness, but rather reprove them" (Ephesians 5:11). HMM