We look at overcoming from a Biblical perspective. To begin to overcome, we must first admit that there is a problem and the first step in that is to know ourselves and our enemy.
"When tempted, no one should say, 'God is tempting me.' For God cannot be tempted by evil, nor does he tempt anyone; but each one is tempted when, by his own evil desire, he is dragged away and enticed." James 1:13 & 14 (NIV translation)
A part of knowing ourselves is knowing that we are born into sin and it is our own evil desires that get us into most addictions. Until we admit that we are sinners and accept the gift of salvation, we cannot be overcomers. Until that happens, we will continue to be deceived by Satan's lies. That is our enemy as we are told that his goal is to devour us.
"Be self-controlled and alert. Your enemy the devil prowls around like a roaring lion looking for someone to devour." 1 Peter 5:8 (NIV translation)
The devil will put on a mask and appear like a fun loving friend to blind you from God's love. He may also use a crisis to cause you to stumble and not look to God.
"The god of this age has blinded the minds of unbelievers, so that they cannot see the light of the gospel of the glory of Christ, who is the image of God." 2Corinthians 4:4 (NIV translation)
Satan is the father of all lies and that is the tactic that he usually uses. He may use an outright lie in some cases but most of the time he will use a half truth which is still a lie.
The first half truth that he will usually use is that of GUILT or SHAME. He will constantly remind us of the bad things that we have done and whisper words of condemnation in our ear. It is a half truth in that we all have done bad things (sinned) but he fails to tell you of the forgiveness and love that God freely offers. It may be some crisis that he uses to get you to turn to drugs, alcohol, food, sex, etc. and once he gets you to take that first step away from God he throws in the GUILT/SHAME. One sin leads to another and, before you know it, you are a groupie having a sex party with a traveling band of four. In the morning he reminds you of the stench and piles on more GUILT/SHAME. The spiral has begun but there is hope which the liar wants to hide.
The second half truth that the devil will use is PRIDE. He may tell you that you can hide the past by putting on a mask just like his and that no one will ever know. Although it is possible (but unlikely) that people on this earth will not know of the things you do, God knows all things and a mask does not fool the Lord. PRIDE may also be used in another way by the faint whisper of one of his favorite lies; "You're not as bad as ________." This is where he gets us to comparing ourselves with others instead of comparing ourselves to God's standard. We can always find someone that we think is worse than ourselves and if we lower the standard enough we just might be ok.
Now that we know ourselves and the enemy, we can look at overcoming addiction and the source of the power to do so. We can get the example from the temptation of Jesus as recorded in Luke 4:1-13. In this example, the devil tempted Jesus with the things of this world and with half truths from God's own word. But, Jesus overcame because of the gift of the Holy Spirit as we are told in the first verse. That same Spirit intercedes on our behalf and calls on the very power of the Creator of the universe. In fact, that same Spirit lives in us if we are children of God.
"Carry each other's burdens, and in this way you will fulfill the law of Christ." Galatians 6:2
We also are a part of the family of God and can call on our brothers and sisters to help us when we struggle. Just as Simon the Cyrene carried the very cross of Jesus, we are called to assist our struggling brothers and sisters.
Just as Jesus did, we can combat Satan and his demons such as drugs, alcohol, pornography, etc. with the very Word of God.
"So from now on we regard no one from a worldly point of view. Though we once regarded Christ in this way, we do so no longer. Therefore, if anyone is in Christ, he is a new creation: the old has gone, the new has come!" 2 Corinthians 5:16 & 17 (NIV translation)
When you come to salvation, this should be one of the first passages that you commit to heart. Then, when satan and his demons try to attack, you can remember the truth in that the old has gone and you have a right relationship with God.
We conclude our look at overcoming addiction with a warning from Jesus' own words. In Matthew 12:43 - 45, we are told that the demons must be replaced by the Spirit or we can end up in worse shape that we started. We see that you can drive out the demons for a time (you may be able to defeat your addictions for a time) but if the demons are not replaced by the Holy Spirit you will not overcome for eternity.