"For we who live are always being given over to death for Jesus' sake, so that the life of Jesus also may be manifested in our mortal flesh." 2 Corinthians 4:11
I'm not exactly sure what this verse is referring to in context (and I don't want to take the time right now to find out), but this difference between our dead old sinful nature and our living spirit in Christ is something I've been thinking about lately. The fact is that our old nature is dead in Christ, having been crucified with him and "the life I now live in the flesh I live by faith in the Son of God."
But the thing I appreciate about this verse is that it says that it is a continuing process, not just a one-time deal.
You know, sometimes I feel like the "real me" is something nobody else ever sees - it's that secret part of me that is controlled by sin, the part of me that I never show to anyone else. But the fact is that that is not the real me at all! No, that part of me is dead...or at least dying. The real me is in Christ, with Christ: the life of Jesus manifest in my mortal flesh - that is the really real me, and not that silly sinful guy who's constantly urging me to do things I don't want to do anymore.
God help me to always realize and remember who I really am: the life of Jesus manifest in my mortal flesh. I am not that sinful self that sneaks up on me and messes with my mind, telling me I'm no good and wanting me to do things you wouldn't want me doing. But I can only do it through your spirit in me, the same spirit that gives me this life. Fill me with your spirit, Father, and give me strength to consider my old nature dead - to give it over to death for Jesus' sake every single day, every single moment of my life, and to truly and constantly live my life by faith in you, Lord. Help me to fully and completely give myself over to you every single day, Father.