Ephesians M/C - Master of Ceremonies. Paul wrote the book of Ephesians. The Ephesian Christians were primarily Gentiles and their lives had not been informed by the Jewish laws or experience. Living in a culture quite contrary to their newfound belief in Jesus Christ, they needed encouragement and guidance to better understand what it meant to live into their new identity in Christ. The Ephesians lived in Ephesus, an important trading and cultural center on the Aegean Sea in what is now western Turkey. It was the center for the worship of the goddess Artemis, or Diana.