How do we know that humans are sinful by nature?

In Romans 7, the Apostle Paul emphasizes that the law is not the source of our sin but instead serves to unveil our true nature. Paul writes in Romans 7:7-8 that he wouldn't have known sin without the law, specifically mentioning coveting as a sin that arises from within. The law highlights our internal struggles against sin, pointing out that even our desires are sinful. This reflects the concept of total depravity, where all aspects of our being are affected by sin. Until the law awakens our understanding, we may mistakenly believe that we are righteous. Recognizing our inherent sinful nature is essential for understanding our need for a Savior.