The problem is, we DON'T have carte blanche to do what we want. The body of flesh is always trying to get it's own way. What we want is righteousness and goodness and love. Isn't that true?
But the flesh wants what it wants, and so we have to sort out what's flesh and what is spirit, the new me.
You speak in terms of the permissibility for our contrary will to defy God. But what I see in the Bible, and it sure makes sense when I look at myself, is that my will has been restored to godliness, while my flesh hasn't. And from the time spent living in flesh, living the flesh life, the flesh mind sounds like my mind, because it used to be me, before I was reborn. And even now it sounds like me, except the thought of the mind of the flesh are not like my thoughts.
My thoughts are, I trust God, I know He loves me, I know He is here with me right now as I'm typing, taking an active role in my life. I'm not alone, I am loved by my Creator. He's promised to always be with me and I believe that.
My thoughts are meditations on His Word, and prayer, conversation with my Creator, rejoicing with thankfulness in my heart for my life and my day, like that.
Thoughts of the flesh mind are, how will I manage, what's going to happen, I don't want to do that again, how can I stop, I have to do something, get something, I need something so bad! This will never end, This is horrible, all wrong, I hate this, I can't stand this, I have to have that, like that. Of course there is so much we can add!
And we are to sort that out, recognizing which are spiritual and which are fleshy, and not let the fleshy thoughts captivate our minds and so lead us into sin.
He will remain in perfect peace, who's mind is anchored on the LORD. If I set my mind on Him, then I'm in the flow with His mind, the mind of Christ. I've found I don't need to take such an active role in my own life as I'm actively setting my mind on God. Simple things, like reminding myself He's here with me in His love for me. I'm His project, I'm being made to show God's glory and grace as He forms my eternal life.
I so look forward to when we do have the carte blanche to do what we want. What we, the children of God, want, more than anything! To be pleasing in the presence of God.
Much love!