But if what I don’t desire, that I do, I consent to the law that it is good. So now it is no more I that do it, but sin which dwells in me. For I know that in me, that is, in my flesh, dwells no good thing. For desire is present with me, but I don’t find it doing that which is good. For the good which I desire, I don’t do; but the evil which I don’t desire, that I practice. But if what I don’t desire, that I do, it is no more I that do it, but sin which dwells in me.
One of the amazing things about becoming a Christian is that God totally changes us in our hearts. We may not realize it at first because there may not be any physical change. What we do realize is that our values change. What we used to not like, we like and what we used to enjoy, now bothers us. This is because when we become Christians we become new creatures. We desire new things. One of the things we desire is to please God rather than to run from Him.
Paul is sharing how he really wants to obey the law but he can’t actually follow through because he also has sin living inside of him. It is the same for all of us who are Christians. We have the desire to do what is right, but just trying to do what is right doesn’t really work. We have this evil living in our bodies that keeps us from being successful.
A great thing to notice is that because we want to do what is right, we are not evil. The evil is that which lives inside of us but, because we don’t want to do evil, it proves that we, ourselves, are not evil. Our old sinful body, which no longer represents our new nature, sabotages our efforts to good. Paul is really making a strong distinction between who we really are and the sin that lives inside. We really are good now, but we still have sin living in us as long as we live in these bodies.