Romans 4 is all about faith and righteousness. Paul essentially argues that being declared righteous by God doesn't come from following the law, but rather through faith. He uses Abraham as an example, explaining that Abraham was counted as righteous because of his faith and trust in God. Paul emphasizes that this concept of righteousness through faith was demonstrated even before circumcision, which is an important piece of the Jewish law. Ultimately, Paul is arguing that righteousness and salvation come by grace through faith, rather than by keeping the law.