“”Church Slavonic (which is an exact rendition of Greek specifically created for liturgical and theological use) and Syriac, were also widely used languages in Christendom.””
Here is some good information on how this comes together from UPENN-Robert Kraft..
http://ccat.sas.upenn.edu/rak//temp/toronto3/report-frame.html
In Search of Jewish Greek Scriptures:
Exposing the Obvious? by Robert A. Kraft
Abstract: Jesus and his earliest followers apparently were Semitic speaking Jews living in Roman Palestine, but their messages quickly spread into the Greek speaking worlds in which Jews had been quite active for centuries. The Greek sources left to us by the early Christian authors, compilers, and copyists include Jewish writings and traditions of various sorts, especially those that later became “canonized.” Greek speaking Jews tend to disappear from our preserved sources in the second century CE, leaving the impression that the gradually dominating Semitic Judaism of the Rabbis has displaced most other Jewish representatives. This paper will challenge that simplistic assessment by drawing together evidence from and about Jewish scriptures in Greek throughout the Greco-Roman period.
More good reading...
THE DEVELOPMENT OF THE CONCEPT Of “ORTHODOXY”
IN EARLY CHRISTIANITY By Robert Kraft
http://ccat.sas.upenn.edu/gopher/other/journals/kraftpub/Christianity/orthodoxy.htm
A few excerpts..
By the year 400 of the common era, there had developed what can be called “classical Christian orthodoxy.” This type of Christianity became mainstream Christianity in both the eastern and the western world prior to the time of the Protestant Reformation. It not only defined its beliefs in terms of standard creeds, such as the so-called “Apostles’ Creed” and the so-called “Nicene Creed,” but it judged the conduct of its adherents in terms of certain prescribed rules and practices for worship and for private life. It not only appealed to a standard collection of religious writings as authoritative, but it also acknowledged the presence of institutional authority in the leaders of the church, an authority believed to have been passed down from generation to generation in a line of spiritual transmission that could be traced back to Jesus Christ himself. It not only actively sought to bring non-Christians into the fold, but it also actively fought to exclude so-called “heretics” and to prohibit such “heretics,” insofar as that was possible, from providing competition for so-called “orthodoxy.”
“modern Protestant Christianity has not been known for its attention to the details of early church history beyond the so-called NT period, despite the real relevance of such a broader awareness”
I want to add one more thing for your reading enjoyment(good stuff)
Greek Scribal Culture in Early Jewish and Early Christian Settings: Continuities and Discontinuities
for the conference on The Early Christian Book at the Catholic University of America, 7 June 2002
http://www.sas.upenn.edu/religious_studies/rak/jewishpap.html
Excerpts
Greek speaking (and reading) Jews existed for centuries within the Greco-Roman world and through the Byzantine period. We have a great deal of secondary evidence for them, from references by outsiders [show Stern, title page] and insiders, to copies (often made by Christians) of actual literary productions (Aristeas, Philo, Josephus, Paul, etc.). Primary evidence in the form of inscriptions, archaelogical remains, and the like is also abundant, especially from ancient Palestine.
Probably the most easily recognized literary activity of Greek Jews in antiquity relates to their translations and transmission of “scriptures,” although that category of writings is somewhat loosely defined in the earliest periods [LXX/OG title page?]. In addition to later references to and copies of these scriptures and related materials, we now have a significant body of actual fragments that almost certainly were produced, or at least commissioned and used, in Jewish circles. A more detailed treatment of these materials is available in my electronic report on “The ‘Textual Mechanics’ of Early Jewish LXX/OG Papyri and Fragments” from which most of what follows has been extracted and adapted.
Protestants even deny the Gospels, the very core of the early Church (Ignatius, Polycarp, Justin Martyr,etc.) as something that doesn't apply to Christains but onyl to the Jews. They have disowned the very essence of the Church and they call themsleves Christians!