If the "flesh" is still in you, then crucify and bury it with Christ...after a true repentance from sin.You have to decide to walk according to the Spirit within you, but if you don’t it’s because the flesh is still here to walk in by default. When you don’t walk in the Spirit it’s because of the flesh that you still have. Galatians 5:17
Then you will be enabled to walk in the Spirit from then on.
If the "flesh" was in control, the Spirit wasn't in you.
We can only serve one Master. (Matt 6:24)