Did you ever try with all your heart to stop doing something you knew was wrong and yet you kept doing it time and time again? Is it possible to actually overcome temptation and be victorious? The Bible says; "Resist the devil, and he will flee from you." (James 4:7) But how do you resist?
I'd like to suggest two ways. The first is the strategy that Jesus used while tempted in the wilderness. Every time Satan proposed sin Jesus shot back with the Word of God. Satan's fundamental tactic is deception so there is no better counterbalance than to proclaim truth.
This is not just spouting off a list of scriptures in rote fashion. To speak the Word with authority you must both know it and understand it. Therefore, study and meditate on God's Word daily.
The next thing is to fill the void. Let's be honest and realize that every sin satisfies a spot in our heart. If it hadn't been attractive it wouldn't have hooked us to begin with. It is said that nature hates a vacuum. After we get to the root of our attraction and reject it, what is going to fill that spot?
The writer of Ephesians understood this well. "Do not get drunk on wine, which leads to debauchery. Instead, be filled with the Spirit." (Ephesians 5:18) The more God's life fills and satisfies our heart, the easier it is to resist temptation. That empty spot inside of us is taken and sin can't find room as easily.
Yes you can be victorious over sin. Be smart about the way you resist the devil. The truth is that when you do, he WILL flee from you.