What ought we say about the gospel and Hellenism? Many things, but this seems like a fruitful line of inquiry:
The gospel is the fulfillment of Israel’s hope. The gospel therefore is known only by its similarity to and difference from the history and faith of the Jews.
The gospel then enters the Greco-Roman world, and it is good news to the Greeks too. And in that setting it is known only by its similarity to and difference from the history and faith of the Greeks.
In this respect, antiquity, Jewish and Gentile, including but not confined to Hellenism, is integral to the meaning of the gospel.
