While you have the light, believe in the light, that you may become sons of light. John 12:36
Sinners enjoy darkness because they think they can hide their sin. They don't tend to enjoy spending time with those in the light either...because they will reveal or expose that sin they're trying to hide.
God is light; in him there is no darkness at all. If we claim to have fellowship with him yet walk in the darkness, we lie and do not live by the truth. But if we walk in the light, as he is in the light, we have fellowship with one another, and the blood of Jesus, his Son, purifies us from all sin. 1 Jn 1:5-7
When you are playing in the darkness....it effects your mood (fear, sadness, etc.) and your eyes grow accustomed to it so that you don't clearly view it as sinful...well, until the comparison of true LIGHT is shared!
For you were once darkness, but now you are light in the Lord. Live as children of light (for the fruit of the light consists in all goodness, righteousness and truth) Eph. 5:8-9
When we attempt to live in the darkness...we stumble and hurt ourselves. Things aren't where we expect them to be, we trip and fall into even darker darkness.
Give glory to the LORD your God before it is too late. Acknowledge him before he brings darkness upon you, causing you to stumble and fall on the darkening mountains. For then, when you look for light, you will find only terrible darkness and gloom. Jer. 13:16