One of the thing I have read in John Owens work is that you need to "Be killing sin or ir will be killing you."
All Christians should be able to say that is a true statement. Another thing I have read is that if you are fighting sin, if you have a desire to fight your sin, you are no longer a dead man, but you are alive. Only those that have been regenerated by the Holy Spirit of God fight their sin. Only those that have been removed from death and darkness and brought into the kingdom of life that is in Jesus Christ have a desire to fight sin. We know that that is the truth. Before we were saved by God, we did not fight our sin, we freely sin, in fact, we had no other options, nor did we want any other options, we weredead in our sins. Only by the grace of God do we now have the ability to fight our sin, to resist it, we should be eternally grateful to God for this being made possible.
So, if you hate you sin and what it does to your relationship with Christ, and you fight it, rejoice, because you know you have been born again. If you have no desire to fight sin, you cannot be born again. You should run to the cross and plead for salvation, Christ will not reject you, for none who truly come to Him, will He reject.
to put off your old self, which belongs to your former manner of life and is corrupt through deceitful desires, and to be renewed in the spirit of your minds, and to put on the new self, created after the likeness of God in true righteousness and holiness. Ephesians 4:22-24
This passage of scripture tells us when we sin, we are not acting in line with who we are but are acting like who we were when we were dead in sin. We are to resist the old man's efforts to regain control of our lives.
We can only effectively resist by faith in the promises of God, thats why reading and meditating on the Scriptures are so neccesary, it is our only weapon. We are reminded also that the beauty, and attraction of sin is a disguise, it is a deception, we are being conned by sin, we are being tricked, its serious because underneath that attraction there is corruption, death, separation from Christ.
This passage also tells us to put on the new man, or self. This is the amazing thing right here the new man is not a better you, it is not anything like you, it was created after the likeness of God in true righteousness and holiness. We need to think about this. God regenerates us, brings us out of death, and gives us eternal life and He places in us a new self that is righteous and holy, its not us, for we are not righteous or holy, we still sin even after we are saved. The Holy Spirit is both righteous and holy - all of the "operations" of God hold some mystery - we cannot figure them out completely that's because He is a Glorious, Eternal, All-Powerful Being and we are not. We do know that He says in His word that not only do we have the Holy Spirit, but that Jesus and the Father will come to live in us, that means that God's purpose for us, Christ's purpose for us is being worked out in us by the Holy Spirit who we have. The point is that we have righteousness and holiness that we need to grow in to, Satan, the world, and our old self are set to stop that growth, we gain the upperhand when we fight them through prayer, fellowship, loving God, loving our neighbor, doing the good works that Christ has called us to. Our sin cannot stop the purpose of God, those that are Christ's will slowly but surely prevail against sin in degrees because the power of sin, which has the whole world under its dominion, has been broken in the lives of His children. God has promised us eternal life because He has the power to make it so, none can stop Him, His purposes will always prevail.
So fight your sin, tell other Christians to fight their sin, take the time to behold the beauty of Christ on the Cross and the deceitful beauty of Satan's schemes, the world's pretty but deadly traps, and the lies of the old self will become dimmer and dimmer and fall away defeated, again, and again, and again.