"So he reasoned in the synagogue with both Jews and God-fearing Greeks, as well as in the marketplace day by day with those who happened to be there… Then Paul stood in front of the Areopagus and said: 'People of Athens! I see that in every way you are very religious. For as I walked around and looked carefully at your objects of worship, I even found an altar with this inscription: to an unknown god. So you are ignorant of the very thing you worship—and this is what I am going to proclaim to you.'”
Acts 17:22-23, Paul preaching (and effectively arguing his case) to the Athenians at the Areopagus (also known as Mars Hill) in Greece