So it resides in a non-physical aspect of our deepest being that, for God's own purposes, is judicially condemned and to be reckoned as crucified but is (for now) left intact within those who are in Christ. We agree on that.
Well... not entirely, even though we're within the same ballpark and pursuing minutiae that is exegetical, semantical, syntactical, historical, and philosophical.
It's the prosopon that is reckoned dead, which includes the physical body and it's conjoinedness to ____________ (fill in the intangible aspect here).
It's isn't sin that's reckoned crucified, but our outer man with sin in its members. That sin in the members is from the soul's functional ascension when the spirit ceased to commune with God's Spirit (spiritual death) for Eve and Adam in Eden. That constitutional disarrangement is how we're born, with an "inverted" soul and spirit. The spirit is "buried" within the soul, and only internally functional.
Where I differ with you is that there definitely are two natures within the believer.
This, then, requires the specific definition of "nature"; and that conversation can't really be had in English unless it's lexically accurate from biblical Greek.
What is a "nature"?
And one problem that arises is that this is Dualism. Yin and Yang. Black Wolf and White Wolf.
That's exaggerated by the fact that nothing in scripture indicates we have two natures, but that we have a new nature. (And we should look at those applicable scriptures.)
The old nature remains and has every bit the mind and will of its own as it did before
This would mean we are now dipsuchos (double-minded). (A double-minded man is unstable in all his ways.) We simply can't have two minds and two wills. We're not two beings (ousios) or two individuals (hypostases) or two persons (prosopoa). Other than medical neurochemical dysfunction, which would be psychopathy such as schizophrenia, we cannot have two minds (or wills).
A "new" nature doesn't mean "another" nature; and there needs to be a clear definiton of nature in contrast to other terms like spirit, soul, mind, will, essence, substance, etc. This is scuba depth, so it isn't light and general. There isn't much room for non-specifics and conceptual vagueries.
And all of THIS (and more) is why we must have an ontological understanding and belief that is the substance of faith from hearing God's Rhema, just as Mary did to conceive Theoanthropos.
Up until now, all we're talking about is hope. Faith is required for us to be IN Christ. Nothing we've discussed about man's constitutional anthropology has touched on anything about us being IN Christ, only having something in us.
There's no translation yet, and the Gospel is that He hath translated us into the kingdom of His dear Son. None of this is us seated in heavenly places in Christ Jesus. None of this is us putting on Christ. It's all internal, and only relative to us and something allegedly added.
The truth is that our hypostasis is translated into the prosopon of Christ, and we're engrafted through the human phusis (nature) and His divine phusis (nature) of His hypostasis into the inherent hypsotasis of God to be partaker of His divine nature.
Our inner man is not seated in us, but in Christ. It's a spiritually literal displacement of our hypostasis by the hypostasis of faith hearing the Rhema as God's hypostasis. This is how the Logos was conceived in Mary for Theanthropos to be born from above and take on humanity with His divinity. We're born from above spiritually just as He was born from above physically.
Our ontology isn't having another nature added to us, but for our inner man to be translated into Christ. We're in Him, so He's in us; including the Holy Spirit which was in Him. As the last Adam (a quickening spirit) and forever High Priest, He deposits the Holy Spirit in our spirit when we believe as the earnest of our inheritance until redemption of the purchased possession; to whit, our mortal bodies at the physical resurrection.
Our new nature is HIM. HIS. We live and move and have our being... IN Christ. We don't just have the Holy Spirit as new wine in our old wineskin and an additional nature added (two human natures?). The nature and the ousia (essence/being) are relative in the same sense as the prosopon and hypostasis are relative. We can't have two natures as a singular human being. Only Christ as Theanthropos could have two natures in one hypostasis as a singular being, and because one nature was divinity.
So that's why we're IN Christ. We have HIS nature, and it's only in us because we're in Him and thus filled with the Spirit.
no one who is truly saved will deny that.
This is an overreach according to your own current understanding, so I'll move ahead.
Only thing is, we can now see it for what it is and each of us knows that "I" am no longer "him."
Right. But that can only truly be ontological. It can't be figurative. It's spiritually literal. So we must believe we are translated as Paul said.
It's the unbeliever, perhaps devoutly religious but who has no new life in Christ, who cannot see it because what he is, is still all that he/she has ever been: a child of Adam in which NOTHING good dwells.
I'm not sure who you're referring to. If you'd clarify, please. The religious? The lost? Those who don't agree that we have two natures and two minds and two wills?
I have a new nature. It's the nature of Christ because I'm IN Christ.