What about here and now? The fact is there is nothing in the Bible called "
sin nature." Some of the dynamic English translations, like the NIV, use a phrase "
sinful nature," but when the Greek is examined the word being translated is "
sarx," or "
flesh." Examine the
NLT's translation of Romans 8:7, for example. The idea of "
sin nature" is an extra-biblical, man-made invention. It's useful to a degree but should not be overgeneralized to mean something scripture never states.
In fact, if you have an older version of the NIV and read Romans 8:12 it will read, "
Therefore brothers, we have an obligation - but not to the sinful nature, to live according to it." but that error in translation has been corrected and the verse now correctly reads, "
Therefore, brothers and sisters, we have an obligation—but it is not to the flesh, to live according to it." You'll not the NLT still has "
sinful nature."
When the NT speaks of "
flesh" it is usually (not always) in the context of "fallen" or "sinful" flesh and not the flesh prior to pre-Genesis 3:7, which God declared good and sinless.
Romans 8:3-4
For what the Law could not do, weak as it was through the flesh, God did: sending His own Son in the likeness of sinful flesh and as an offering for sin, He condemned sin in the flesh, so that the requirement of the Law might be fulfilled in us, who do not walk according to the flesh but according to the Spirit.
There was no sinful flesh prior to Genesis 3:7.
Romans 7:5
For while we were in the flesh, the sinful passions, which were aroused by the Law, were at work in the members of our body to bear fruit for death.
There are no sinful passions in the flesh prior to Genesis 3:7. It was by one man's disobedience that sin entered the otherwise good and sinless world (
Rom. 5:12). So the concept is useful, but it's not exactly scriptural and there needs to be limits placed on its usage. Two examples of abuse would be the Gnostic view everything physical (like human flesh) is ungodly and worthless, or of lesser value, and the perverted version of total depravity that misguidedly says humans can do nothing good at all ever. It is always more accurate, more scriptural to use the word "flesh" in its scripturally provided context of the fall, or Adam's disobedience
(I tend not to use the word "fall" for the very same reason I don't use "sinful nature").