Here's why:
* Alexander the Great's conquests: The spread of Greek culture under Alexander the Great (4th century BC) led to the widespread adoption of Greek as an official language in many conquered territories, including the Levant (where Judea was located).
* Common Language of Trade and Administration: Koine Greek, a simplified form of Ancient Greek, became the common language of commerce, administration, and intellectual discourse throughout the Hellenistic world.
* The New Testament was written in Koine Greek: This indicates its importance as a language accessible to a wide range of people across diverse regions and cultures.
While Aramaic was the primary language of everyday life for many Jews in Judea, Koine Greek was used in official settings and served as the language of communication between different ethnic and linguistic groups. The New Testament, written for a diverse audience, was therefore written in Koine Greek to reach a wider range of people.