No, the flesh is not the old nature. A dog has a nature to turn and lick up its vomit. A hog has a nature to wallow in a mire. A lost person has a nature to sin, go against God. All these examples are what is natural by birth to each example. In the case of a sinner (lost person) the nature feeds off the flesh. Both the flesh and the nature are in agreement.
There are plenty of nations in this world that eat dog. They eat the meat. That is "flesh." There is nothing inherently evil in the flesh of a dog. Dogs are not evil. God created all his creation and looked at it and claimed that it was very good. That included dogs. It was man that fell; man that sinned; man that acquired a sin nature. A dog doesn't have a spirit like man. Your example does not fit. There is nothing sinful in meat (flesh). Every time you sit down to eat: steak, hamburger, chicken, etc., are you eating sin? All of that is flesh--the flesh of an animal. Flesh is not sin. Sin does not reside in the flesh (meat) of an animal or man. When the Bible speaks of flesh, it is normally speaking of a flesh nature; sin nature; depraved nature; Adamic nature, etc.
For the human who is born again it is no longer natural for them to sin.
Yes it is. I don't know of anyone (saved or unsaved) who doesn't have a nature to sin. We all struggle against it. Unless you are God you struggle against sin. If you say you don't, you are probably lying to me right now. In almost every epistle that Paul wrote, writing to Christians, he wrote about sin, rebuking Christians of sin, telling Christians how to overcome sin. This was no accident. The sin nature is never eradicated; not until the resurrection occurs.
A Christians does not sin because it is their nature. Thye sin because they give into the flesh, but it comes with a price.
The flesh (nature) and the sin nature, and the old nature, and the Adamic nature, are all the same thing. They are just different words describing the same thing. You still have a flesh nature or sin nature. And unless you attribute your sin to God, you still have a sin nature.
Old things are passed away and all things have become new. This false teaching that we have an old sin nature is why Paul is so upset in Romans. People using a belief and term to justify their sin and in this case "old sin nature."
You have misunderstood Scripture. Where in Scripture do you find Christians making excuses for their sin? Where is Scripture do you find Paul being "so upset"?? You are reading into Scripture things that are not there.
Listen to the Spirit through Paul;
Romans 6:1-4 What shall we say then? Shall we continue in sin, that grace may abound?
God forbid! How shall we, that are dead to sin, live any longer therein? (let me point out that the old nature is dead, but the flesh is still alive. New wine (the new nature) has been put into old wineskins (the flesh) and one day they will burst and new wines skins will be given.)
We are to act as if we are dead to sin. Sad to say most Christians don't as is evidenced by this chapter and the last part of chapter five. If they were already dead to sin and didn't have to act dead to sin, then Paul would have no need to write what he just wrote. It would all be redundant. He wrote it because they were not acting dead to sin.
Know ye not, that so many of us as were baptized into Jesus Christ were baptized into his death?
This verse simply points out the symbolic teaching of baptism.
Therefore we are buried with him by baptism into death: that like as Christ was raised up from the dead by the glory of the Father, even so we also should walk in newness of life. ( I need to point out something here. The word should is not in the Greek and it makes the passage sound different then is intended. It is not saying we should walk like this, but many do not. It is saying we who are born again walk like this. The new birth requires a new walk.)
Maybe so, but it can't force one to walk that way. Every Christian must make their own choice how they are to walk. The can make the choice to walk carnally for a time, in which case God, their Father, will chastise them according to Hebrews 12. There is such a thing as a carnal Christian. This is stated very clearly (4 times in 4 verses) in 1Cor.3:1-5, where Paul addressing Christians says, "You are carnal."
For if we have been planted together in the likeness of his death, we shall be also [in the likeness] of [his] resurrection:
Very true. That is speaking of the resurrection, not how we live right now.
Knowing this, that our old man (this is the sin nature) is crucified with [him], that the body of sin (this is the flesh) might be destroyed, that henceforth we should not serve sin.
we should not serve sin. That is where the emphasis is. But some Christians still do. That doesn't take away their salvation. Like the Corinthians they are carnal. They need to repent. Much of the language is symbolic here. It has to do with baptism, and what baptism represents.
In almost every other passage Paul speaks of being crucified with Christ in an active tense. It is something to be done every day. It is not something, like salvation or justification, that happened once. For example, in 1Cor.15:31:
I protest by your rejoicing which I have in Christ Jesus our Lord,
I die daily. (1 Corinthians 15:31)
Jesus taught the same thing:
And he said to them all, If any man will come after me, let him deny himself, and
take up his cross daily, and follow me. (Luke 9:23)
--It is not a one time act. Take up your cross daily. A cross is an instrument of death. The disciple was to crucify himself daily--every day he was to put himself to death; every day he was to put his old nature to death. That is what Paul had to do, even after Pentecost came. The truth is still the same today. We are not immune from the old nature that dwells within us.
For he that is dead is freed from sin.
And how are you dead. What is the definition of the word "dead."?
At salvation the old nature died. That man died with Christ! This is part of the symbolism of water baptism.
No it isn't. We will always have that old nature. What was buried at baptism is our former life of sin.
It is no longer the nature of the believer to sin.
Are you claiming to be sinless?
However we are left with the flesh which we are responsible to control and not it us.
The flesh is the flesh (sin) nature. They are one and the same thing. You are playing a game of semantics in which you cannot win. Flesh as meat is not spoken of here. Sin does not reside in the periodic table.
This is why it is so uncomfortable for a believer to sin. We have to go against our nature and give into the flesh and the flesh is very seductive.
That is because it is a sin nature--the Adamic nature.
However we have a promise that we will not be tempted so greatly that we have to give in.
1Cor 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].
That is the promise that God gives us that we can overcome sin; that we can have the victory over it. It is there for us. Does every Christian claim it or take advantage of this promise? No, they don't. Many succumb to their testings and trials anyway. Many remain as carnal Christians.
So there is no old sin nature in a believer, but we yet reside in these corruptible bodies and we have the ability to control them and are expected to do so.
There is a flesh nature as you admitted. That is the same thing as the old sin nature which you do not want to admit. All you are doing is playing word games.