Perhaps we could look at a few other issues to help.
For example, it has been suggested that Jesus had to be born of a virgin in order to avoid this "sin nature".
I view the Virgin Birth to be a matter that it was God Who took up residence in a human body, whereas in procreation we have one man and woman becoming "one." In other words, had there not been a Virgin Birth, we would have had the spirit usually generated in procreation and the Spirit of God in the same flesh.
I do not view the Son of God as co-habitating with the "spirit of Jesus Christ," so to speak, but that He was fully God, and His body was fully human just as Adam's was when he was created.
This suggests that sin is a biological issue rather than a response to temptation based on the desires of the flesh (
James 1).
Which is contrary to the teachings of Scripture.
While one might call the fact that man will inevitably sin a "sin nature," the way I see it is that men sin because they do not have the ability to be righteous. They can do good, but, there is nothing stopping them from doing evil as well.
That is where the Eternal Indwelling comes in:
Ezekiel 36:27
King James Version (KJV)
27 And I will put my spirit within you, and cause you to walk in my statutes, and ye shall keep my judgments, and do them.
We are created in Christ Jesus unto good works. It's not just a matter of us deciding to do good, it is a matter of God directing our paths. Jonah "did good" unwillingly, but completely lacked an eternal perspective in regards to the Ninevites. We, on the other hand, look into eternity and understand that a physical perspective doesn't over-shadow the eternal. We love our enemies because God loves them, and because He has placed love in our hearts.
Are there any passages that suggest sin is passed down genetically?
No.
Scripture speaks of the wicked as being of their father the Devil. Does this mean Satan or his demons actually fathered children (i.e., was Daniel Parker right)?
No.
It is no different than Abraham being a "father" to those who have faith, or Paul being a "father" to those he led to Christ. It is figurative. Satan was the father of lies, the originator, and they were just like their "father," liars.
So the nature of sin needs to be explored (is it an act of the will in disobedience to God or is it a genetic predisposition passed down biologically).
Here's something to consider: unknown sin. In other words, men can sin and not even know it. What is sin? It is the transgression of the will of God. How do we know not to sin? By knowing the will of God, first and foremost, and that is where we stand in a better position than most men: because God has shown us His will, and has placed His Spirit within us that we might fulfill that will.
How do men without the Spirit react to the authority of others? They mostly reject it. How much more true is that in regards to the will of God. "Don't tell me I can't __________(fill in the blank!" Don't tell me I have to __________(fill in the blank)!"
But if we have the mind of Christ, not only do we know that will, but...we agree with it. You couldn't have told me when I was young that there was anything wrong with my life. Hey, I was a pretty good guy. I didn't hurt anyone. But, the truth is that guy was someone I despise to this day. Why? Because God showed me the reality of who that person was.
I did "good" things sometimes. But, I didn't realize the sin in my life, and that sin was contrary to the will of God.
Also, what we are referring to as "nature" needs to be addressed.
I would start that topic out with saying that there are two natures in view, that which is natural (that we are born with), and that which we have when we are immersed into God in eternal union, and thus become new creatures. Just as the natural man can sometimes do good, even so the new creature can sometimes do evil. But these are two entirely different natures, because one has eternal life, and the other was dead.
Perhaps the reason this "sin nature" is foreign to Scripture is how the term is used (Scripture only refers to the "flesh" and the "spirit"). Maybe it is an issue of definitions.
Like I said, we can call natural man's proclivity to sin as a "sin nature," but, the reason he sins is because he is born separated from God. It is not something he is "born with" that causes him to sin, it is something he is born without. Rather, it is Someone he is born without.
The babe in the womb isn't destined for eternal judgment because they have sinned, they are destined for eternal judgment because they are separated from God. Praise God that in the case of babes who die in the womb we can trust the Just God to extend the same grace bestowed to Old Testament Saints, who also died still separated from God.
God bless.