As you read this part of Athanasius’ treatise, it helps if you understand something of the divine madness of the Delphic oracle or something both of Greek philosophy and the worship of the Greek gods. I’ll move straight to his conclusion.
But as to Gentile wisdom, and the sounding pretensions of the philosophers, I think none can need our argument, since the wonder is before the eyes of all, that while the wise among the Greeks had written so much, and were unable to persuade even a few from their own neighbourhood, concerning immortality and a virtuous life, Christ alone, by ordinary language, and by men not clever with the tongue, has throughout all the world persuaded whole churches full of men to despise death, and to mind the things of immortality; to overlook what is temporal and to turn their eyes to what is eternal; to think nothing of earthly glory and to strive only for the heavenly.
Even Plato convinced only a very few. Christ, on the other hand, used men who were not clever to persuade churches full of those who despise death.