'Darkness' in the Bible

This is the message [of God’s promised revelation] which we have heard from Him and now announce to you, that God is Light [He is holy, His message is truthful, He is perfect in righteousness], and in Him there is no darkness at all [no sin, no wickedness, no imperfection].

If we say that we have fellowship with Him and yet walk in the darkness [of sin], we lie and do not practice the truth;

On the other hand, I am writing a new commandment to you, which is true and realized in Christ and in you, because the darkness [of moral blindness] is clearing away and the true Light [the revelation of God in Christ] is already shining.

The one who says he is in the Light [in consistent fellowship with Christ] and yet habitually hates (works against) his brother [in Christ] is in the darkness until now.

But the one who habitually hates (works against) his brother [in Christ] is in [spiritual] darkness and is walking in the darkness, and does not know where he is going because the darkness has blinded his eyes.