<<absence of light>>
Physical darkness is a lack of light. In fact, light dispels the darkness and shines brighter in the darkness (Jn 1:5). Spiritual darkness is described as a living in rebellion and apart from the light of God's love in Christ; it is being unconnected to God through Jesus.
Darkness can't remain where the light of God's truth shines
the light of the world conquers all spiritual darkness and oppression (which is a hallmark of Satan), setting free of darkness (characterised as Satan's evil ways) all who come to Him (Jn 8:12, 12:46; 1 Thes 5:4; Heb 2:14,15; 1 Jn 3:8).
Sinful man tries to walk and even hide in darkness, yet God sees through darkness (Ps 139:11,12; Prov 2:13-15, 4:19; Jn 3:19,20; 1 Jn 1:6). Before we were born-again we were stumbling along in spiritual darkness, not acknowledging the truth but now we are in the light we must ensure there is no darkness of sin lurking within whereby the devil can legitimately gain a foothold (Eph 4:27, 5:8,11; 1 Jn 2:11). As Christians we are to get rid of all the habits of darkness (the ways of the carnal old life) and walk in the radiant light of Christ for “What fellowship can light have with darkness?” (Rom 13:12,13; 2 Cor 6:14; Eph 4: 22-24). As believers our struggle is against the powers of darkness in the world, yet with Jesus we are victorious (Eph 6:10-12).
Live in the light with Jesus
The works of darkness are to be cast off and replaced with the armour of light for we are now beacons of the spiritual light of Christ (Rom 13:12,13).
Even when we don’t know which way to go and ‘we’re figuratively in the dark’ trust in the Lord, the Light of the World (Isa 50:10).
The eternal fate of the lost is also termed outer darkness, a condition of great sorrow and loss accompanied by "weeping an gnashing of teeth" (Mt 8:12, 22:13, 25:30,41; Jud 1:13). This description of hell indicates it is a place of immense sorrow, indescribable spiritual agony, unspeakable suffering and unending pain. This is the eternal destiny of all who reject Christ (Jn 3:18,36). There is no third option. By choice we either turn to Jesus for salvation or are doomed to hell and all the horrors it encompasses.