Therefore there is now no condemnation for those who are in Christ Jesus. Romans 8:1
I stand before God the Father as if I had never sinned. As if the sinful nature had not been passed down from me by Adam. As if I had never lied, stolen, lusted, been prideful or deceptive. As if I had never dishonored my parents or blasphemed His name. This does not mean that God simply does not remember my sin anymore, how can a omniscient God simply forget the horrific abominations I have committed against Him? That is impossible! But rather God the Father chooses in His perfect sovereignty to look rather upon Jesus' blood poured out at Calvary rather than my insufficiency to be holy as He is holy. It is there that God the Father can pardon me, it is because of Christ's death that I have eternal life. Let me not think that my sin is "a little thing" for it took the blood of an infinitely holy, pure and righteous God to justify or redeem me.
Now I do not think I've reached some spiritual state of holiness where I cease to sin (oh wouldn't that be nice!). Rather I am attempting to combat sin in my own life with right thinking. If I know who I am in Jesus than I have clearly drawn the battle lines with sin, because sin is in direct opposition to who I am in Christ. I cannot serve to masters, that is impossible. While I do not claim to be sinless or perfect (far from it!) I cling to the promise in 1 John 3:2 that "We know that when He appears, we will be like Him, because we will see Him just as He is."