I think its time we went through what you quoted out of context, verse by verse.
2 Cor 5:14 For the love of Christ compels us, because we judge thus: that if One died for all, then all died; 15 and He died for all, that those who live should live no longer for themselves, but for Him who died for them and rose again.
16 Therefore, from now on, we regard no one according to the flesh. Even though we have known Christ according to the flesh, yet now we know Him thus no longer.
16 Therefore, from now on, we regard no one according to the flesh. Even though we have known Christ according to the flesh, yet now we know Him thus no longer.
Paul isn't saying that their are some who no longer have indwelling sin (the sin nature). What is saying is let's see the lost, not as they are, but how thy are "in Christ in the heavenly realms". See Eph 2:6
17 Therefore, if anyone is in Christ, he is a new creation; old things have passed away; behold, all things have become new.
The "if" has to do with whether one has believed in Christ or not. If one has placed his/her faith in Christ, he/she is a new creation. Where? In himself or herself? No! "In Christ". We are a new creation, i.e., holy, and blameless" in Christ. See also Col 1:21,22
Why does this not refer to the believer? Because "all things" have not become new in the believer!
For example, the believer is still mortal. The believer still has a sinful nature. The believer still is falling short of God's agape (which is sin). So the only thing that has changed in the believer is his/her heart. That simply mean his/her "mind". The heart is now in harmony with God's agape, but the flesh is still in harmony with the love of self.
So you aren't a new creation yet, in yourself. You receive this "new creation" at the resurrection when you are changed.