19 Therefore, those also who suffer according to the will of God shall entrust their souls to a faithful Creator in doing what is right. 1 Peter 4:19 (NASB95)
When we come to our end we discover His beginning. You cannot force the end of your self will. You are not meant to be without a will nor self-willed. The problem, if any, resides in the self. Discovering who you were and how that worked helps you to know who you are in Christ and how that works.
When I was a child of God's enemy I thought enemy thoughts. That enemy thinks he is independent of God's rule, able to decide to do good or to avoid evil on his own. I was duped, I thought it was me thinking and wrestling with those thoughts. Then I realized Christ had died for all my stupid thoughts and sinful behavior. It was over and done with by Him and in Him.
If my mind stays attached to sin defining me, I stay suffering Christ's death to sin. But when I realize my new self is in Christ Himself, being Himself in and through me, I also get to simply be a willful me again. The only difference is that this new 'me' is a slave to Righteousness. So much so that I not only want to do what Father is doing but know who is doing it even though it feels like I am doing it independently of God.
So then, as I once did life thinking I was independent of Satan's spirit of error, yet a slave to his will, I now know that I can be just as duped into thinking that I am not a slave to God, but able to do God at will. But now I know that is a lie and I am a slave to God's will.
The liberated life is His life liberating me to be me. This is His Being faithful.