That which is born of the flesh is flesh. This is the nature and character that we have from Adam. The nature by which sin entered the world and death by sin - we became by nature - sinners.
That which is born of the Spirit is spirit. When we are born again of the Spirit, a new creation is created within us that has a different nature and character than that which we received from Adam - 2 Peter 1:4 Whereby are given unto us exceeding great and precious promises: that by these ye might be partakers of the divine nature, having escaped the corruption that is in the world through lust. We have escaped the corruption that is in the world through lust for we are seated in heavenly places in Christ [Eph. 2:6]- in the flesh or in the Spirit? In the Spirit we are seated in heavenly places in Christ because of that new creation. This is said in the present tense although it hasn't happened yet; it is one of those exceeding great and precious promises and is said in the present tense to cement the surety of the statement.
When speaking of the "flesh" there are different names used within scripture same as when speaking of the "spirit". I thought that it would be good to take a look at these two natures in comparison.
"flesh" vs "Spirit" - the "flesh" cannot please God - So then they that are in the flesh cannot please God. [Rom. 8:8]; the "flesh" profited nothing - [John 6:63b]; in the flesh dwelleth NO good thing [Rom. 7:18] The flesh has at it's root - Sin and only produces sins as its fruit. "Spirit" is in contrast and opposition to the "flesh". As said above the "Spirit" is created in us from God and is therefore the "divine nature". The new nature - the divine nature is perfect and unable to commit sin - It is born of God. Whosoever is born of God doth not commit sin [as his fruit]; for his seed [the new nature, i.e. Spirit] cannot sin, because he [or it - the new nature] is born of God. [1 John 3:9, 1 John 5:18,19] The other day I was called a Gnostic for saying this - I looked it up - still don't think I am because throughout scripture - there are comparisons of the two natures.
"old man" vs "new man" - And that you put on the new man, which after God is created in righteousness and true holiness. [Eph. 4:24] And have put on the new man which is renewed in knowledge after the image of him that created him. [Col 3:10] The "new man" is also called the "new creation" as seen in Colossians 3:10 - we are renewed in knowledge by the Spirit of God that created the Spirit within us. Therefore if any man be in Christ, he is a new creature; old things are passed away; behold, all things are become new. [2 Corinthians 5:17] For in Christ Jesus neither circumcision availeth any thing, nor uncircumcision, but a new creature (creation). IOW - thing done in the flesh - circumcision or uncircumcision profits anything - the only profit is being born again of the Spirit - the new nature - the new creation created in righteousness and true holiness and created after the image of Him that created it.
"inward man" vs "outward man" - For I delight in the law of God after the inward man. [Rom. 7:22] For which cause we faint not; but though our outward man perish, yet the inward man is renewed day by day. [2 Cor. 4:16] That he would grant you, according to the riches of his glory, to be strengthened with might by His Spirit in the inner man; [Eph. 3:16]
Our outward man perishes day by day - it is but flesh - but our inward man is to be renewed - nourished and replenished day by day with grace and strength by the Holy Spirit. The inward man delights in the law of God [Rom. 7:22] but the outward man is not subject to the law of God [Rom. 8:7]. THE CONFLICT within man until death or Christ's return! O wretched man that I am! who shall deliver me from this body of death? - I thank God He will deliver me through our Lord Jesus Christ.
"the mind" vs the "carnal mind" - These relate to our acts, conditions, and characteristics in relation to our thoughts, mental activities, reasonings, and imaginations. The carnal mind is enmity against God for it is not subject to the law of God, neither indeed can be. [Romans 8:7] For to be carnally minded is death; but to be spiritually minded is life and peace [Contrasted to "flesh" (as "spirit" is) because it is that which is inward and invisible.] This "mind" (Spirit) serves the law of God [Romans 7:25] and delights in it [Rom. 7:22] - But I see another law in my members [flesh], warring against the law of my mind [Spirit], and bringing me into captivity to the law of sin which is in my members [flesh]. It is a battle the flesh against the Spirit - that's why in Galatians Paul asked them - Are ye so foolish? having begun in the Spirit, are you now made perfect by the flesh?
We cannot be made perfect in the flesh - sometimes it is a struggle to make our flesh line up with our Spirit. For the flesh lusteth after the Spirit, and the Spirit against the flesh: and these are contrary the one to the other: so that you cannot do the things that you would. [Gal. 5:17] Our relationship with God is a walk - This I say then, Walk in the Spirit, and you shall not fulfil the lust of the flesh. [Gal. 5:16] We are to let that new creation, that new man lead us as it is renewed day by day and strengthened by the Holy Spirit. We will reside in this body of death until Christ's return or our deaths - UNTIL then, Let us be like Paul - Let us "Fight the good fight of faith, lay hold on eternal life, whereunto thou art also called, and hast professed a good profession before many witnesses." And we will be able to say "I have fought a good fight, I have finished my course, I have kept the faith." Remember that we are kept by the power of God - Blessed be the God and Father of our Lord Jesus Christ, which according to his abundant mercy hath begotten us again unto a lively hope by the resurrection of Jesus Christ from the dead to an inheritance incorruptible, and undefiled, and that fadeth not away, reserved in heaven for you who are kept by the power of God through faith unto salvation ready to be revealed in the last time. 1 Peter 1:3-5
By teaching a duel nature doctrine you are upholding the basic principle of Gnosticism.
Human being do not have a duel nature. We have a spirit (that which drives us), a consciousness (mind), and a fleshly body (our vessel). Sin is not found in the flesh and the flesh does not have at its root sin. That is pure gnosticism.
The flesh has natural passions and desires and to be fleshly it to allow oneself to be driven by those passions and desires like a beast. The reason there is "no good thing" in the flesh is that apart from the light of God we would be beast animals operating on lust alone. The flesh itself is not evil, it was Augustine of Hippo who brought that garbage into Christian doctrine and theologians have developed it since then.
In Romans 7 Paul is speaking of a man who is addicted to the lusts of the flesh and therefore has a natural disposition towards them in rebellion to God. That wretchedness is overcome through the Spirit of Life IN Jesus Christ. In other words we shift from being a self serving beast in rebellion to God to being God driven via the Spirit having crucified our beast self.
The word "nature" in the Bible is the Greek word "Phusis" and it literally means GROWTH. A "sin nature" is the natural disposition to sin which develops through the long practiced habit of sinning. Sinning becomes hard wired in a human being for several reasons. The human brain adapts to our behaviour. In the same way that the brain of a cocaine addict physically changes and adapts due to the reinforcement of the unnatural increase of dopamine (which brings a feeling of comfort/well being) upon pathways in the brain, the brain of a sinner similarly adapts. To go against such a nature is extremely difficult and is only possible through the Spirit of life in Jesus Christ.
This is why the "old man" cannot be reformed. It has to die once and for all in repentance whereby we yield our hearts 100% to God. We are then energised for victory and over time we will become hardwired to the service of God whereby the old temptations lessen.
The problem with dualist notions is the flesh itself is blamed for sin. Under this delusion people naturally abdicate their responsibility in having "sold themselves int bondage through choice" because they believe they were "born in bondage apart from choice" and thus approach the sin problem as victims not criminals.
A victim mindset in a criminal excuses further rebellion because they perceive the rebellion as being "natural" and thus they will teach "sin you will and sin you must." Hence the disconnect between "manifest deeds" and the "state of the spirit." That disconnect is gnostic dualism in all its glory, or in all its perversion dressed up as glory.
You see you are saying things like this...
We have escaped the corruption that is in the world through lust for we are seated in heavenly places in Christ [Eph. 2:6]- in the flesh or in the Spirit? In the Spirit we are seated in heavenly places in Christ because of that new creation. This is said in the present tense although it hasn't happened yet; it is one of those exceeding great and precious promises and is said in the present tense to cement the surety of the statement.
That is Gnosticism 101. You are believing the lie that your salvation lies in a "spirit which is abstract" and thus not "reflected in the flesh." You claim "it hasn't happened yet" because you are upholding the view that the FLESH is holding you back. You twist Peter around by claiming "the escape has not happened yet" when Peter says that it has. The philosophy you believe forces you to distort the Bible.
The Gnostics taught that matter was evil and that the spirit was good. They would teach that one could perfect the spirit via knowledge and via exercising the will (self denial or asceticism) yet they always taught that sinning would continue due to being embodied in evil flesh. John the Apostle refuted these lies in his first epistle by stating...
1Jn 2:3 And hereby we do know that we know him, if we keep his commandments.
1Jn 2:4 He that saith, I know him, and keepeth not his commandments, is a liar, and the truth is not in him.
1Jn 2:5 But whoso keepeth his word, in him verily is the love of God perfected: hereby know we that we are in him.
1Jn 2:6 He that saith he abideth in him ought himself also so to walk, even as he walked.
John made it clear that the walk must match the profession. One cannot be sinning in the flesh and be pure in the spirit like the gnostics taught.
John wrote...
1Jn 2:15 Love not the world, neither the things that are in the world. If any man love the world, the love of the Father is not in him.
1Jn 2:16 For all that is in the world, the lust of the flesh, and the lust of the eyes, and the pride of life, is not of the Father, but is of the world.
1Jn 2:17 And the world passeth away, and the lust thereof: but he that doeth the will of God abideth for ever.
The Gnostics denied this because they taught one simply cannot do with will of God because the flesh itself restricted it. They believed the flesh suppressed the light of the soul. They taught "sin you will and sin you must."
John wrote...
1Jn 3:6 Whosoever abideth in him sinneth not: whosoever sinneth hath not seen him, neither known him.
1Jn 3:7 Little children, let no man deceive you: he that doeth righteousness is righteous, even as he is righteous.
1Jn 3:8 He that committeth sin is of the devil; for the devil sinneth from the beginning. For this purpose the Son of God was manifested, that he might destroy the works of the devil.
1Jn 3:9 Whosoever is born of God doth not commit sin; for his seed remaineth in him: and he cannot sin, because he is born of God.
1Jn 3:10 In this the children of God are manifest, and the children of the devil: whosoever doeth not righteousness is not of God, neither he that loveth not his brother.
The key word above is MANIFEST. That word blows gnostic doctrine out of the water. The children of God are MANIFEST because they DO righteousness. The deeds of the righteous prove their faith. Modern theology utterly rejects it and tries to spiritualise it away exactly like you are doing in your post.
What you are actually doing is arguing in favour of sin without realising it. You are beholden to a salvation which is not salvation at all. You are under a very dangerous deception, a deception which destroys souls.
Believe the Bible and turn away from all these notions developed by men.
What did Jesus actually teach? he taught "blessed are the pure in heart for they shall see God." Jesus taught heart purity.
Believe Jesus. Keep His commandments. Walk as He walked and let your light shine before men.
Flesh is just the meat on our bones. It is through the flesh we are tempted. Yielding to temptation involves a choice. God does not suffer us to be tempted above what we are able but always offers a way of escape.
1Co 10:13 There hath no temptation taken you but such as is common to man: but God is faithful, who will not suffer you to be tempted above that ye are able; but will with the temptation also make a way to escape, that ye may be able to bear it.