Addiction is caused by our yielding to the pleasures of the flesh. Our flesh loves pleasures. When we allow ourselves to be controlled by these addictions, we become influenced by them. As we respond to the desires of our flesh this way, addiction sets in.
To overcome addiction, we need self-discipline. We must discipline ourselves and not yield to every form of pleasure that our flesh desires. Discipline is one of the ways of putting ourselves under control. If we don't control ourselves, then other things will control us. A person that is not disciplined is like a house that doesn't have windows. In such a house, everything enters.
We should allow the word of God to flush out evil things from our hearts. We should read our Bible daily. When we read the Bible daily, we learn out of the Word of God and the Word of God which we are listening to cleanse us from the influence of addiction.
We also need the power of the Holy Spirit to overcome addiction. The Holy Spirit gives us power and strengthens our spirit to refuse being addicted to harmful substances.