RO 7:14 We know that the law is spiritual; but I am unspiritual, sold as a slave to sin.  I do not understand what I do. For what I want to do I do not do, but what I hate I do.  And if I do what I do not want to do, I agree that the law is good.  As it is, it is no longer I myself who do it, but it is sin living in me.  I know that nothing good lives in me, that is, in my sinful nature. For I have the desire to do what is good, but I cannot carry it out.  For what I do is not the good I want to do; no, the evil I do not want to do--this I keep on doing.  Now if I do what I do not want to do, it is no longer I who do it, but it is sin living in me that does it.
RO 7:21 So I find this law at work: When I want to do good, evil is right there with me.  For in my inner being I delight in God's law;  but I see another law at work in the members of my body, waging war against the law of my mind and making me a prisoner of the law of sin at work within my members.  What a wretched man I am! Who will rescue me from this body of death?  Thanks be to God--through Jesus Christ our Lord! So then, I myself in my mind am a slave to God's law, but in the sinful nature a slave to the law of sin.
I want to speak of something here that has been on my mind now for some time. What I am speaking of concerns the two natures that we seem to struggle with in our lives as believers. I watched a movie the other day, one that probably most of us have seen at one time or another. I am speaking of the classic Robert Louis Stevenson story of the man who struggled with two natures that battled within him. We all know the story of how this doctor had somehow come upon a serum that would cause a dramatic change to come about in his personality. He was at first a very mild-mannered man who kept to himself and practiced medicine. Somewhere along the way he wanted a change though. He wanted to become a new person. He wanted a dramatic breakthrough, and he certainly found one! But it wasn't the type of change or breakthrough that he had wanted. He discovered that after he partook of this potion that the change that came over him was much more than he could handle. He became someone or something, that was totally strange to himself. He became a monster, if you will. He had secretly fallen in love with a woman who lived in his household that was one of the maids that worked there. In the end, she saw the horrible transformation that took place with this man after he had taken this serum. She saw that there were actually "two men" and not one.
What I wanted to write about here though, is how we ALL struggle with another nature within us. Paul describes this very well in the above section from Rom. 7. " For what I do is not the good I want to do; no, the evil I do not want to do--this I keep on doing. " --19 So if I do the things that I do not want to do then how on earth am I able to do the things that God would have me to do? Quite a perplexing question, and quite a perplexing dilemma if I do say so. Obviously this is something that we can't do on our own. Wouldn't it be something IF we could take a potion that would change us into Mr. Right or Miss or Mrs. Right? But of course there isn't such a thing. We have extreme make-overs that help people become more attractive on the outside, but they can't change the inner person, the one that really matters. Only the Holy Spirit can affect that change. Only the Holy Spirit can change us from glory unto glory:  And we, who with unveiled faces all reflect the Lord's glory, are being transformed into his likeness with ever-increasing glory, which comes from the Lord, who is the Spirit. But then the real question may be "do we really want to change?" Perhaps we do, but are we willing to allow the Holy Spirit to change us? The pruning of a tree is something that probably appears to be a drastic measure, but in the end the result is something that yields the fruit that is necessary for the tree to produce. The same is true with out natures. We actually don't have to go on letting Mr. Hyde take the upper hand in our natures. While he is still there, we can allow the true Mr. Jekyl to become all that he is supposed to be through the new nature that God wants to do "in us." Then we won't need any serums or seminars, or "quick fixes." Let Him do the work; He knows what He's doing.