Ephesians 2:1-3 NASB95
And you were dead in your trespasses and sins, [2] in which you formerly walked according to the course of this world, according to the prince of the power of the air, the spirit that is now working in the sons of disobedience. [3] Among them, we, too, all formerly lived in the lusts of our flesh, indulging the desires of the flesh and of the mind, and were by nature children of wrath, even as the rest.
2 Peter 1:4 NASB95
For by these He has granted to us His precious and magnificent promises, so that by them you may become partakers of the divine nature, having escaped the corruption that is in the world by lust.
In those verses in Ephesians 4, Paul explains that all unsaved people are by nature children of wrath. He even makes it clear in verse 2 that our fallen nature was kissed by the Prince of the power of the air. There was something satanic about our fallen nature.
In Christ, we have become new creatures who are partakers of the divine nature. 2 Corinthians 5:21 says that we have become “the righteousness of God in Christ.”
The definition of the word “nature” in the dictionary is – (the fundamental qualities of a person- The identity or essential character of a person – the essence of who you are – including ways of thinking, feeling, and acting.)
The Greek word for “nature” in both the Ephesians and the 2nd Peter passage means – “the native essence of a person.”
Colossians 3:3-4 makes it really clear that you in Christ aren’t the same person that you were before you became a Christian. You have actually been “born again,” and you have become a new self in Christ. Colossians 3 says, “For you have died (the old fallen, corrupt self and its corrupt nature died on the cross with Jesus) and your life (your new self) is hidden with Christ in God.” The new you can only be found in Christ. The essence of your new nature as a Christian is the divine nature of Jesus. It is the righteousness of God in Christ. Christians don’t sin by nature; they sin by choice. All those “ought to’s” in your heart to do the right thing are actually your true “want to’s.” Those righteous desires represent your true essence, your new nature in Christ. That’s the real you. There is still a law of sin that lives in the members of our body, and it cries out to us, through our flesh, to live as if we were still the Old Man. But it’s a lie, an illusion, trying to get you to live as if you were still the old fallen self. It is not the true you, because the essence of who you are is in the union with the nature of Jesus. The miracle of the mutual indwelling of us in Christ and Christ in us defines you.