We do not have a sin nature, we have sin residing in the flesh. The word “sin nature” is not even in the Bible. If you’re going to use it, use the term the Bible uses.
Everything that we were in Adam, the “old man,” or “old self” as the Bible calls it, is dead. We died to sin when our old man died, the day we believed in the Lord Jesus Christ. Now we are in Christ. We were given a new heart and a new spirit under the New Covenant. Israel as a nation will be given the same as Jeremiah and Ezekiel prophesy, when Jesus comes back to rule on this earth.
We are to walk—that is live our lives—in the power of the Holy Spirit in us. We have a new walk, a new lifestyle. If there’s no change, there’s no salvation. Do we still sin? Yes, unfortunately we fail to control the lusts of the flesh. Sometimes it is a struggle. But there is power in the Word of God, if we will study it and believe it, and there is power in the Holy Spirit who indwells us, and there is the victory that was won over sin on the cross.
BUT—we do NOT continue the way we were, as the Scriptures I gave plainly say in Ephesians 2—we have everything we need for life and Godliness.
We aren’t called saints for nothing.
All true believers are on the road to maturity, or being perfected in Christ. He promises to finish what He has begun in us. We are being conformed into the image of Christ and will be in our glorified bodies, perfect or complete, when we see Him either in the air or when we are raised.
I have two passages for you that deal with this. I think these speak for themselves. Please forgive my formatting.
James 4 tells us this:
17 Anyone, then, who knows the good he ought to do and doesn't do it, sins.
1 Corinthians 8
9 Be careful, however, that the exercise of your rights does not become a stumbling block to the weak. 10 For if someone with a weak conscience sees you, with all your knowledge, eating in an idol’s temple, won’t that person be emboldened to eat what is sacrificed to idols? 11 So this weak brother or sister, for whom Christ died, is destroyed by your knowledge. 12 When you sin against them in this way and wound their weak conscience, you sin against Christ. 13 Therefore, if what I eat causes my brother or sister to fall into sin, I will never eat meat again, so that I will not cause them to fall.