How do you define “sin nature”? How does a person reveal their “sin nature”?
Concupiscence is the effect of Original Sin on human nature, meaning we’re drawn to sin. We have a free-will and can say ‘no’ (God’s grace assisting us) to sin.
Usually, its defined as the flesh. As in the spirit is willing but the flesh is weak.
For if you live according to the flesh, you will die; but if
by the Spirit you put to death the misdeeds of the body, you will live
For what the law was powerless to do because it was weakened by the flesh, God did by sending his own Son in the likeness of sinful flesh to be a sin offering. And so he condemned sin in the flesh, 4 in order that the righteous requirement of the law might be fully met in us, who do not live according to the flesh but according to the Spirit.
Jesus -
They answered him, “We are Abraham’s descendants and have never been slaves of anyone. How can you say that we shall be set free?”
34 Jesus replied, “
Very truly I tell you, everyone who sins is a slave to sin. 35 Now a slave has no permanent place in the family, but a son belongs to it forever. 36 So if the Son sets you free, you will be free indeed.