The Bible teaches that humans consist of three parts: the body, the soul, and the spirit. This helps us understand what happened in the fall, how sin occurs in our lives, what God does through regeneration, and why we are still awaiting glorification.
Romans 3:10-12 is not about the Calvinistic ideas of Total Depravity or Total inability. Yes, universal sin is taught, but Paul’s point is to put Jewish people on the same footing as Gentiles regarding their standing before God. To see this, we need to understand the context of Romans 3 in light of the overall structure and argument of Paul in his letter to the Romans.