First, Jesus didn't go against Old Testament law, he fulfilled it (see Matt. 5:17) and was thus the embodiment. Old Testament law was not local gov't law, Roman law was. Two things you must keep in mind, the New Testament was not the New Testament when Jesus lived, it became the New Testament when the writings were compiled, meaning that Jesus was living in Old Testament times, but the culture was dominated by the Roman empire. Furthurmore, understand who the book of Romans is written to, the Romans. The context of the scripture and the book is Paul explaining how the Romans, though they were non-Jews, how they could receive salvation through grace by Christ (Romans 10:8-12) and how they were "grafted into the tree" (Romans 11). The scripture in question is admonishing them that, though they've made this radical change in their system of worship (remember mythology and the roman theocratic system?) they were still subject to Roman law. In Acts, there is an instance where Paul was beaten, and eventually caused a lot of trouble for his aggressors because he was a Roman citizen and they didn't know it, meaning that they were subject to trouble (see Acts 22:26). This is a loose connection, but it's an example of Roman law.

Apocalypse

"When purpose is not known, abuse is inevitable . . ."