The belief in a sin nature is like trinitarianism. It is something that must be in existence first, and then Bible verses are sought out which are seen to "prove" the doctrine. Just like the trinity. Yet, mysteriously, there is not one passage where any prophet, apostle, or Christ himself taught that mankind is born with a "sin nature". There is no passage anywhere that defines this so-called "sin nature". There aren't even any passages which describe the doctrine of a "sin nature".
The sin nature doctrine leads necessarily and inevitably to the Immaculate Conception doctrine, in order to explain how Christ somehow missed inheriting a sin nature from His mother. Since all descendants of Adam possess a sin nature from birth, it necessarily follows that humans inherit the sin nature from their parents. It likewise follows that Christ, since He was born of a woman and is a biological descendant of David, and thus of Adam, Christ must necessarily have inherited this same sin nature. But that of course is not possible. Therefore, to avoid the dilemma of confessing either that Christ had a sin nature on the one hand, or that Christ was not genuinely human on the other hand, a doctrine of Mary's "Immaculate Conception" is created whereby Mary was supernaturally conceived in her mother's womb "without the taint of original sin". That way, Jesus could be both fully human and yet without inheriting a sin nature. Hocus Pocus, a la peanut butter sandwiches, voila!
The sin nature doctrine is a Roman Catholic doctrine, pure and simple. It was essentially invented by Augustine, who had not shaken off his Manichaean dualism from his gnostic days. His brand of gnostics believed that there was something inherently evil about flesh itself, something evil about material (physical) things. Yet the Bible does not speak of the human body itself as evil, but rather the "body of sin" or the "flesh" by which is meant the life of sin.
Romans 8:5-9
(5) For they that are after the flesh do mind the things of the flesh; but they that are after the Spirit the things of the Spirit.
(6) For to be carnally minded is death; but to be spiritually minded is life and peace.
(7) Because the carnal mind is enmity against God: for it is not subject to the law of God, neither indeed can be.
(8) So then they that are in the flesh cannot please God.
(9) But
ye are not in the flesh, but in the Spirit,
if so be that the Spirit of God dwell in you. Now if any man have not the Spirit of Christ, he is none of his.
Here it is clear that being "in the flesh" has nothing whatsoever to do with being a physical human with a real physical body. Since receiving the Spirit places a person in the category of "NOT in the flesh" yet people who receive the Spirit do not suddenly become disembodied spirit beings, it necessarily follows that "flesh" is used MORALLY, not biologically.
Paul clearly states the apostolic doctrine of the voluntary nature of sin:
Romans 6:19
(19) I speak after the manner of men because of the infirmity of your flesh: for
as ye have yielded your members servants to uncleanness and to iniquity unto iniquity; even so now yield your members servants to righteousness unto holiness.
Previously, we YIELDED ourselves to serve iniquity and uncleanness. This is clearly a voluntary action, meaning it is a choice of the will. Voluntarily surrendering to unrighteousness produces a bondage:
Romans 6:16
(16) Know ye not, that to whom ye yield yourselves servants to obey, his servants ye are to whom ye obey; whether of sin unto death, or of obedience unto righteousness?
If you YIELD yourself (voluntary choice of the will) to serve something, you become that something's bond-slave, whether of sin unto death, or of obedience unto righteousness.
The doctrine of an inherited sin nature makes sinning involuntary. And if it is involuntary, it has no more any kind of moral character, no more than eating, drinking, or farting has. And therefore, there can be no guilt attached to sin, since you cannot be GUILTY in a moral sense (that is, you cannot be TO BLAME) for things that you cannot in any way shape or form avoid. If you cannot help yourself, then you are not truly TO BLAME. Blame is nothing else than the moral character of not doing what you OUGHT to do. But you cannot "ought to do" something you literally cannot do.
If God commanded you to flap your arms and fly about the sky, you could not possibly obey. And your failure to obey cannot possibly be a cause of BLAME. To BLAME you for failing to flap arms and fly would be unjust, UNRIGHTEOUS, because you cannot be held to account for that which you literally cannot do. How can it be said you OUGHT to do that which is literally IMPOSSIBLE for you to do?
Jude 1:14-15
(14) And Enoch also, the seventh from Adam, prophesied of these, saying, Behold, the Lord cometh with ten thousands of his saints,
(15) To execute judgment upon all,
and to convince all that are ungodly among them of all their ungodly deeds which they have ungodly committed, and of all their hard speeches which ungodly sinners have spoken against him.
To properly convict a person of their sin, they must actually be to blame for their sin. There is a reason the old KJV uses the term "convince" instead of "convict". The reason is that a proper conviction requires proof "beyond any reasonable doubt". And the Final Judgment will include sinners themselves being without excuse. They will themselves be convinced, or convicted, of the truth of God's Judgment.
But if the sin nature doctrine is true, every sinner has the most plausible excuse for their sin, and will never be convinced of their actual guilt. The conscience, which recognises guilt and innocence, right and wrong, praise and blame, can never be convinced that the unable are to blame.
No more than you would assign moral guilt to a retarded child for their actions.