To call Greek a dead language is to take a narrow-minded, exclusively pragmatic view of time and of life and death (at least of the life and death of languages). A language is only dead when it has passed from human memory, leaving no literature or descendants. Perhaps we could say that Hittite and Tocharian are dead langauges, because their literatures are scanty and they are known by few, though even they life for ardent Indo-European philologists, after their fashion. The life of a language is a relative thing. To call Greek a dead language is to admit that one knows no Greek and to imagine that it cannot be known and , indeed, is not worth knowing.
Greek is a living language not only because it never died but continues to develop and change and can still be heard in its heir, Modern Greek, but also because it has left us a literature that is part of our common heritage and that continues to influence the way we think, speak, and write.
This is what I’ve been trying to say all along!