After the triumphant declaration Paul makes in chapter 6, that we are no longer slaves to sin, but should be slaves to God’s righteousness, he then confesses that in spite of that truth, he still wrestles with sin. We see ourselves in his autobiographical confession.
The gist of what Paul says, I think, is that sin still resides in his flesh. And that sin nature is at war with the freedom God has given him in his inner being. It ends up like this:
For I don’t understand what I am doing. For I do not do what I want—instead, I do what I hate.
Romans 7:15
We each find ourselves in this situation in spite of our freedom. Not always, and hopefully less and less as we mature in Christ. But … as John says in his first letter, “if we say we have not sinned, we make him a liar and his word is not in us.” (1 John 1:10). But John also tells us, “But if we confess our sins, he is faithful and righteous, forgiving us our sins and cleansing us from all unrighteousness.” (1 John 1:9) And so we have a path to be cleansed and made newly righteous. Thank God for that.