1Jn 1:5 This is the message we have heard from Him and announce to you, that God is Light, and in Him there is no darkness at all.
1Jn 1:6 If we say that we have fellowship with Him and yet walk in the darkness, we lie and do not practice the truth;
God is Light and in Him is no darkness... This is the true foundation of our saving faith in our Lord Jesus Christ. God is Light. He is pure and holy, perfect in every way. No darkness, or evil, can be found in Him.
When we give up our lives and seek after the heart of God, what are we really pursuing? Nothing other that the definition of true perfection. God, holy and just, came down from His high place to save us from ourselves. He became light so we could be free from the darkness that we have chosen to live in.
If we claim to be in fellowship with Him, to be walking in the divine nature of God and yet are filled with any sort of darkness, then we are pretending to be a follower of God and we are a liar. Where He is there can not be any darkness. Just as a small amount of light fills a dark room, so Christ must fill those dark places in our hearts.
Examine my heart oh Lord and see if I have any darkness within me.