There were great differences in the culture of the Greco-Roman world from the Jewish culture that the Apostles lived in. They faced a great challenge evangelizing a culture with a vastly different cosmology. The primary state-sponsored religion of the empire was emperor worship. Most people adhered just to get along. Emperor worship evolved as a natural progression of the pantheon mixed with the humanistic cosmology of the Greek philosophers. The “gods” of the Greco-Roman pantheon were worshiped primarily by middle/ lower class agrarian people. The “gods” of the pantheon were nothing more than glorified humans with very human characteristics, including their sin nature. Greed, envy, lust, jealousy, etc. were common to the pantheon. The pantheon gods were worshipped for their power. Thus, it would be natural to look upon the emperor as a god. The humanistic/ atheist philosophies of the Epicureans and the Stoics were adhered to primarily by the educated and academic classes. These upper class folks would have been the type that Paul witnessed to at the Areopagus.
It is important to understand that most Romans were not very satisfied with their cosmology. The emperor could be a cruel tyrant. He was noted for authoritarian control, the taking of property and oppressive taxation. The gods of the pantheon had not served the masses well in defending them.
It is amazing to consider how God prepared the 1st century Roman world for the spread of His gospel. Most scholars credit the Pax Romana, the peace of the empire, which enabled the evangelists to move about the empire freely. But there were other important contributing factors. The existence of the Jewish diaspora was crucial in making people familiar with the one God of the Jews. The neighborliness of most Jews and the unique nature of their God appealed to many disillusioned Romans. The God of the Jews was unique in that He was not only powerful, but He was “holy”, that is completely different than humans and without the sin nature of the gods of the pantheon. But, perhaps most importantly, the one desire for true freedom that God places in every human heart was what motivated Romans to receive the gospel message with gladness. True freedom from outside oppression and inner bondage can only be found in Christ. The Romans were ready to hear about a new King that offered eternal freedom. The message for which the Apostles were martyred was that there was a new King. They were not martyred for telling people how to get to heaven. The emperor could not have cared about that. But, another King was a threat.
Our society today has many parallels to ancient Roman. People have been promised security by an over arching and controlling government. They have neither security nor freedom and they are disappointed with the god of the state. They need to hear the message that there is a King that offers true and everlasting freedom.