You and I are new creations. This man was not born and raised to know all about living this way, for my flesh resisted into adulthood. Growing up seems a lot easier than the transition into the Way, as I remember ways of learning like using memory cards to learn to add numbers. But when I began to comprehend who Jesus is, I entered into a realm of existence college didn't prepare me for. No job prepared me for this life. I plunged into it when the Father called me to Jesus.
I was a lost man when I met Jesus. When I say that it startles folks. Some folks don't like admitting that. My Old Man knew it without being coached to understand it all the days I remeber in my youth. I experienced Jesus in me, and submitted to public baptism in water as an adult, though at age twelve was baptised without understanding. Everything is new, of a different kingdom now. But there's a sad part that can't just go away, and that is this body of mine must die, reaping what I sowed by any sin I committed, death being the wages of sin. He is still there, accountable for sin, waiting to die the first death, as will my body he used too, if the Lord tarries, which I suppose is quite natural since many people I knew did that with or without Christ. So that old self is well buried, quite unnaturally.
Thank God that Old Man is at least now dead to sin in that I have power by the Holy Spirit in me to keep him powerless, in his grave lying there undead physically. I know because I left him in that lake water in 1976. I now will not plan to yield my body to sin like he liked to do. I know the remedy if I do sin. But that doesn't make my body live as long as I would prefer. I am not that Old Man any longer, but a new man in Christ in this same aging flesh body, reckoning, accounting by the word of God that former self is dead, buried, and this new man arose with Jesus to new life.
Nothing about this life in Christ is natural. The natural fails us, body and soul and spirit. What I, the real me inside this body of flesh, have now is eternal life, a wonderful hope, a healed conscience, a satisfied memory to which God has added explanations, understanding, forgiveness, cleansing, and growing love for people who helped me along the way, who at the time I might not have appreciated enough. That isn't natural either, but is the work of God renewing my mind.
There is no other human "nature" entity, no dual living persona, the "Old Man" being the former mindset that was corrupted the first quarter of my life. That is best described by personifying it as a creature. I was changed inwardly by the greatest miracle of all.