Now while Paul was waiting for them at Athens, his spirit was provoked within him as he saw that the city was full of idols. So he reasoned in the synagogue with the Jews and the devout persons, and in the marketplace every day with those who happened to be there. Some of the Epicurean and Stoic philosophers also conversed with him. And some said, “What does this babbler wish to say?” Others said, “He seems to be a preacher of foreign divinities”—because he was preaching Jesus and the resurrection. And they took him and brought him to the Areopagus, saying, “May we know what this new teaching is that you are presenting? For you bring some strange things to our ears. We wish to know therefore what these things mean.” Now all the Athenians and the foreigners who lived there would spend their time in nothing except telling or hearing something new. (Acts 17:16-21)
In Athens then – as in our modern world now – apart from idol-worshippers and the devout there were also cultured people who followed many philosophies, such as the seeking of material good, and obedience to the moral duty of man. When Paul spoke, what struck them was his preaching about a man, of one who rose, he said. That a dead body had risen was something new to them, and so strange that some of them took his words to be mere meaningless rubbish.
So they took him to the Areopagus, an open-air place where a crowd could enjoy hearing him, and after that perhaps the Areopagite Court would pass a verdict on what he had to say.