Koine Greek

Koine Greek, meaning common Greek, is the simplified, widely spoken form of Greek that emerged following Alexander the Great's conquests in the fourth century BCE, spreading Greek as a lingua franca across the eastern Mediterranean and Near East and gradually leveling many of the more complex grammatical distinctions and regional dialect variation found in earlier Classical Greek, the Attic-based literary standard of fifth-century BCE Athens.

Koine Greek belongs to the Hellenic branch of the Indo-European family, and its status as the common trade and administrative language of the Hellenistic and later Roman eastern Mediterranean world made it the natural language of composition for the entire New Testament and for the Septuagint, the pre-Christian Greek translation of the Hebrew Bible produced for Greek-speaking Jewish communities in Alexandria and elsewhere, a translation whose existence gave early Christianity, itself emerging from a Greek-speaking as well as Aramaic-speaking Jewish milieu, a ready-made Greek Old Testament to cite and build upon. Koine Greek's relative grammatical simplicity compared to Classical Greek made the New Testament accessible to a socially broad ancient readership rather than only the classically educated elite.

The Septuagint, traditionally said to have been produced by seventy or seventy-two translators working in Alexandria in the third and second centuries BCE, rendered the Hebrew Bible into Koine Greek for a Greek-speaking Jewish diaspora that had lost fluency in Hebrew, and became the Old Testament text most early Christians actually read and quoted, since Greek-speaking Christianity spread faster and further in its first centuries than direct engagement with the Hebrew original among non-Jewish converts.

The entire New Testament, including the four Gospels, Paul's epistles and the Book of Revelation, was composed in Koine Greek within a few generations of Jesus's death, giving Christianity's foundational scripture a specific linguistic register whose particular grammar and vocabulary, including terms such as agape for selfless love and logos for divine reason or word, became deeply embedded in later Christian theology across languages that subsequently translated these Greek concepts. Koine Greek remains the language of the Eastern Orthodox Church's own scriptural and patristic textual tradition, studied directly by Orthodox seminarians and scholars rather than approached only through later Byzantine or modern Greek intermediaries.