Actually the fruit isn’t merely of the spirit.
He made us human in body soul, and spirit.
Through faith alone in Christ alone we can do all things in His Plan by doing the right thing, in the right way, at the right time, in the right place,..by faith alone in Christ alone.
Start there.
He is the one who grows us.
Discouraging faith alone in Christ alone simply encourages a worldly or carnal thinking or encourages doubt, which also removes us from fellowship with Him.
I don't discourage faith alone. I'm confident that we are justified by faith alone. That it is only our faith in christ that saves us. But I also believe that if we have that faith we will grow and be the good tree that produces good fruit. That is the evidence of true faith.
It is way to easy to say "I believe, I'm saved"... and then live with no evidence of that. The idea that a person can claim faith in Christ and then live however they want does much damage. It produces the "tares". I agree it is God who grows and matures us. But he only does that where we let him. And those who live a lifetime without letting Christ mature them never knew him. That's the way I read it.