Romans 2 springs a trap on any religious person who read Paul's lists of sins at the end of Romans 1 and thinks it was not about them. Paul calls them out for making themselves judges when they are also guilty. He shows that God will judge everyone, including those under the law, based on their works. This prefaces this letter's theme of salvation by grace, through faith, rather than by works. Many benefits come with having the law, but only if those under the law keep it. Jewishness—circumcision—must be an inner state, not just an outer one.