If you have the Spirit of God residing in you, you are children of the light. That light is like a flash light that shines into the darkness and reveals sin. It's very simple. The battle comes when we do not want to be obedient to God's light and want to stay in the darkness. We can't find satisfaction in the dark because we now have the Holy Spirits illumination. It's impossible. It's like having a lantern under the blanket! Believers who stray from the light, which is God's truth, are the most miserable creatures on the planet. Angry because no matter what they do the light follows them around exposing sin and they can never truly ever enjoy it again.
Colossians says that "God delivered us from the power of darkness, and hath translated us into the kingdom of his dear Son." He has something better for us. Peace, joy, contentment, love and purpose. People who walk in the light get to their destination. If you aren't getting victory over an addiction or lifestyle have you submitted yourself to God? Or are you trying to live in your own strength without Him? I would encourage you to lay your pride down and accept that you are not in control. By faith believe that God does exist and has a satisfying plan for your life. Until you do, the battle will rage on.
"Then spake Jesus again unto them, saying, I am the light of the world: he that followeth me shall not walk in darkness, but shall have the light of life." John 8:12
"Submit yourself to God, resist the devil and he will flee from you." James 4:7