What does Acts 17:20 mean?

Paul is in Athens, alone. Jealous Jews from the synagogue in Thessalonica ran him out of Berea, even though the Berean Jews were willing to investigate his teaching about Jesus' fulfillment of the prophecies of the Messiah (Acts 17:10–15). Luke stayed in Philippi (Acts 17:1). Timothy is in Berea—or possibly Thessalonica (Acts 17:14; 1 Thessalonians 3:1–2). It's unclear where Silas is (Acts 17:14; 18:5).

Not being one to sit still, however, Paul has already shared about Jesus in the synagogue in Athens as well as the Agora. It was in the Agora that the Epicurean and Stoic philosophers found him and aggressively invited him to the Areopagus to share his beliefs. They think he's a babbler: someone who picks up bits and pieces of philosophy from the Agora and puts them together like a bird picks up seeds. Even though they don't expect much, they love to hear new, surprising worldviews (Acts 17:16–19, 21).

Paul's position is precarious. One the one hand, it is against Roman law to promote the worship of a foreign god. On the other hand, because of its cultural significance, Rome granted Athens the status of a free city. But on the third hand, the law against foreign deities is older than the Roman Empire. In 399 BC, Socrates had been tried and convicted on this same hill. Xenophon, in Memorabilia, described the charges: he "does evil, for he does not acknowledge the gods whom the state acknowledges, while introducing other, novel divine beings."

In the first century BC, the Roman statesman Cicero had outlined the Roman Empire's assertion of the law in De Legibus, ii. 8: "…let no one have private gods—neither new gods nor strange gods, unless publicly acknowledged, are to be worshipped privately…"

Fortunately, even though the philosophers have brought Paul to the court where the most serious crimes are tried—including, legend says, the trial of murder against Ares—they seem more curious than confrontational (Acts 17:21). They think Paul's wrong, but they don't persecute him.