In order to answer this puzzling question, first we must know the etymology of the word “bible” as it will give you a good idea, why we say “Bible” instead of some other thing.
early 14c., from Anglo-L. biblia, from M.L./L.L. biblia (neuter plural interpreted as fem. sing.), in phrase biblia sacra “holy books,” from Gk. ta biblia to hagia “the holy books,” from biblion “paper, scroll,” the ordinary word for “book,” originally a dim. of byblos “Egyptian papyrus,” possibly so called from the name of the Phoenician port from which Egyptian papyrus was exported to Greece. The port’s name is a Gk. corruption of Phoenician Gebhal (modern Jbeil, Lebanon), said to mean lit. “frontier town” (cf. Heb. gebhul “frontier, boundary,” Arabic jabal “mountain”). The Christian scripture was refered to in Gk. as Ta Biblia as early as c.223. Bible replaced O.E. biblioðece “the Scriptures,” from Gk. bibliotheke, lit. “book-repository” (from biblion + theke “case, chest, sheath”), used of the Bible by Jerome and the common L. word for it until Biblia began to displace it 9c. Figurative sense of “any authoritative book” is from 1804. Bible Belt first attested 1926, reputedly coined by H.L. Mencken.
The holy book of Christian was first called the Bible by the Greeks. But that is not all, it all started when the Phoenicians had found a way to make paper out of papyrus plant in the city of Byblos. And that is why later the Greeks called the paper Biblios. As the time passed somewhere between 350 AD and 400 AD the word bible had originated and was used to describe soley the Christian scriptures.
Greeks play a role in almost everything we see in our daily life.