Light vs Dark

           I saw this tweet the other day that said, "You can never gain cold, you can only have the absence of heat. It made me think that maybe hatred doesn't exist, and it's only the absence of love." So if this is true, darkness is just the absence of light. So technically, darkness is nonexistent. 
        John 1:5 says, "The light shines in the darkness, and the darkness can never extinguish it." If all of this is true, how can darkness overtake the light of Christ? 
        One way I think of it is you can turn on and off a light, but you can't flip a switch and turn on and off the darkness. When you turn off the lights, it gets dark. Which similarly applies to our spiritual light. When you turn away from God, your flame burns out and darkness takes it over. But when you turn to God, your fire burns bright. Keep your light shining brightly and keep your life set on God.
        "Turn your face towards the Son and all the shadows will fall behind you."