John 1:5 says, 'The light shines in the darkness, and the darkness has not overcome it.'
The light is the greek word 'phos' which we found john 1:4. The word shines is the word 'phaino' and it means to bring forth, shed light, and to shine. The word darkness is the word 'skotia' and it means darkness. Finally the word overcome is the word 'katalambano' and it means to lay hold of, to obtain, take possession of, and to understand.
I take this verse to be true on a scientific level, but also a spiritual level.
Scientifically we can see this happen all the time. Anytime you turn on a light it lights the room and it overcomes the darkness. You never turn on a light and it the darkness stays pitch black. We are assuming here that your light is obviously in working order.
Spiritually it has two meanings for me. I believe that the light does overcome the darkenss, as in a conquering mentality. I also believe that the greek word for overcome in the ESV and comprehend in the NASB, means that the 'darkness' can't understand it.
1st the light overcomes all darkness. If we believe this to be true in our lives then we have power over all sin and addicitions and all darkness in our lives. God has always had victory over all forms of darkness and we must bring the victory to where darkness is in the world. I believe that God is everywhere at all times, but for some reason we has chosen to use us to display his light/glory. This means that we have the priviledge of showing people what God looks like by being light in their lives.
2nd the light can't be understood by the darkness. This is why people that don't know God act the way that they do. They can't understand it. Now I believe that as we have previously looked at, that all people can understand aspects of truth, but I am talking about saving knowledge and understanding of who God is. They aren't followers of Jesus, because they don't understand who Jesus is. This is where only God's grace can remove this cloud of misunderstanding. We can't yell or push someone enought to believe in who Jesus is. They don't understand it. Our job is to emit the light of God, but it is God's mercy that we allows them to see it and understand it. This is where we pray for those we know are hurting and are walking around in the dark and have no direction for their lives.
God is the light of the world and everything else is darkness. This goes straight to what Jesus says in Matthew 5:14-16. It says, 'You are the light of the world. A city set on a hill cannot be hidden. Nor do people light a lamp and put it under a basket, but on a stand, and it gives light to all in the house. In the same way, let your light shine before others, so that they may see your good works and give glory to your Father who is in heaven.'