Keeping simple lets discuss this.....what is a sin nature.
Example 1...Family crash lands on tropical island that has no people. Mom and dad die.....little boy 4 years old lives and grows up on island by himself.....Now what is this sin nature going to cause that boy to do between 4 - 30 years old?
The phrase, sin nature, isn't in the Bible.
Sin is in the world because Satan is lord here.HSatan is here because he was cast out of Heaven where sin gained life,expression, with Satan's rebellion against the rule of God.
When God cast Satan and his fellow rebelling angels out of Heaven , that rebellious adversarial impulse,spirit, was cast out too. God in every sense cleaned house. And sent them all to earth.
We are born sinless.
Yet we are also born as flesh bearing a soul within.Because of that mortal density,flesh,bone, even though the silver cord connects us to Holy Spirit(God), our human nature is atuned to the energies,powers, of the world.
Because what is in the world is what we depend on to survive. We defer to those things by that default setting, so to speak.
Because we take the world so seriously and are preoccupied with availing ourselves of what it has to offer so to survive the flesh, we do not hear the voice of God.
That is so because we are separated from God in our natural flesh state of focus and consciousness toward the world that holds primacy. Because we need sustain ourselves here. Exploiting what the world has to offer while living off the world.
Which as an aside is why the world is now in peril. We stopped living with the eotld, belonging to it, and started living off the world as gluttonous parasites.
That only changes when God's spirit enters in. And gives us perspective.He's always been there within us. We are merely preoccupied with the noise and visuals of this reality and don't necessarily hear him.
But he always knows us.
When we are newborns,children, the things of the world are at the disposal of our parents so to take care of us.
When we're old enough to rationalize and make decisions for ourselves, knowing right from wrong, that is when our human nature unites with the world created by God to sustain the human, being as one created in God's image and likeness.
There is no sin nature.
There is the human nature predisposed to the dual atmosphere of the world. Sin isn't a being,or a living spirit as Satan is. Sin is an atmosphere in contrast to the atmosphere of righteousness.
Sin is acting contrary to God's directives for right living.
The flesh knowing ourselves mortal and impermanent seeks out gratification in the time we have left.
Our perspective is one of, we see it,we believe it, we want it.
The transcendent, the non-visible, doesn't catch you myopic selfish attentions by nature in this flesh.
But it can. Because we are linked to the source,God, by our very being that is entirely of and from God our creator.
When God gets our attention, the bridge is made. We come to realize we are more than perishable flesh ,bone,and carnal appetite.
And that is when, like as when we were innocent babes learning how to crawl and then walk as we gained our confidence, so too do we slowly learn to put that spirit of God, like a transperancy laid over a painting, first in our walk in this life. And therein walk more in the spirit than in the flesh that takes this world so seriously.
That's how I see it anyway.:)