Walking in darkness is really you ignoring God and loving the things of this world.

When you love someone you want to be with them, if you can't you are always thinking about them and how soon can i see them. Walking in darkness is why you make mistakes, who you marry,who you trust, who you hang out with.
You won't make mistake hanging out with God for {his word is a light unto your pathway a lamp unto your feet. No surprises.