Flesh versus Spirit

I'm no Greek expert... Well, actually, I don't know Greek at all anymore, so that's a silly way to start this post. It comes from my curiosity to what Paul meant when he said "flesh". Is he talking skin and muscle? Is he talking about our physical cells and DNA? After the comment (Thank you!) about Romans 7, I went back to re-read it. Here's the part that stands out to me (v. 15-25):

"For I do not understand my own actions. For I do not do what I want, but I do the very thing I hate. Now if I do what I do not want, I agree with the law, that it is good. So now it is no longer I who do it, but sin that dwells within me. For I know that nothing good dwells in me, that is, in my flesh. For I have the desire to do what is right, but not the ability to carry it out. For I do not do the good I want, but the evil I do not want is what I keep on doing. Now if I do what I do not want, it is no longer I who do it, but sin that dwells within me.

So I find it to be a law that when I want to do right, evil lies close at hand. For I delight in the law of God, in my inner being, but I see in my members another law waging war against the law of my mind and making me captive to the law of sin that dwells in my members. Wretched man that I am! Who will deliver me from this body of death? Thanks be to God through Jesus Christ our Lord! So then, I myself serve the law of God with my mind, but with my flesh I serve the law of sin."

It seems like, as Paul describes the civil war inside of him, who he is in Christ wants to do what is right, desires what is good. His heart/spirit/inner being is good and wants what is good, but this thing called "sin" or his "flesh" is not his identity, though it is a constant thorn in his side, it seems. I don't understand exactly how that works itself out. It is clear, from a realistic standpoint, that it doesn't matter theologically what you call it - we all seem to experience a tension between our desire for doing what's right and our actual actions of doing what is wrong. I think what I am learning is that there is freedom and power, to understand that we are good at our core now. In our inner being, in our spirit, if Christ's spirit dwells within us, we are new and pure. Sin has lost it's ability to condemn us and identify us. We are no longer guilty by association (with the sin that was in essence our master, our boss). I think why my thoughts are leaning in this direction are because if I believe that I am still desperately wicked and evil, I have experienced a lifeless guilt, a wallowing in my sinful condition. I echoed what Paul said, "Wretched man that I am!"... but the thing that the church didn't teach me when I was growing up is that Paul didn't end the book of Romans at chapter 7. He continues into chapter 8 with, "There is now, therefore, no condemnation for those who are in Christ". He goes on and makes some more spiritual/logical connections of thoughts to verse 9, "You, however, are not in the flesh but in the Spirit, if in fact the Spirit of God dwells in you."...

All this is simply to say, we are free. Sin is real, don't get me wrong, and it is obviously still present in my life. I still feel that tension. But there is something liberating to understand that sin can't control me. I don't have to sin. I am no longer a prisoner to my flesh. I can choose to obey it and give into it, but that's like choosing to do work for an employer you don't work for anymore. The paycheck from that employer is death, so to speak. Anyway... this isn't completely solid in my mind/heart, but I'm finding that there is a freedom in it that I previously did not know when I consistently reminded myself that I am wretched. I'm sure it is a balance, as most things are, but for too long, my pendulum has swung way too far to the side of believing that God's spirit within me doesn't change how wicked I am. If that's true, that's not very good news...