To preface this post, note that I am an Orthodox Christian who converted from Lutheranism in 2008, after a 9-year in-depth exposure to Orthodoxy in a Serbian-American community.
1. Judaism had several different streams just before and during Jesus’ earthly ministry. The ENTIRE Septuagint was translated and produced by Hellenistic Jews, NOT Christians. So there was NO “Christian revisionism”, even though post-Second Exile Jews do not accept the Septuagint.
2. Orthodox Christians read from the first five books of Moses in certain services (not the Sunday Divine Liturgy), some of which (such as in Holy Week) are very important services attended by most of us. We also commemorate as Saints many figures in the Torah, including Moses, Aaron, Abraham, Isaac, and Jacob, Joseph, etc. The Lutheran Church-Missouri Synod commemorates some of the m as well.
3. Christians believe that God speaks to us in ALL human languages—ever since the Day of Pentecost (also a Jewish feast) after Jesus’ Resurrection.
http://en.wikipedia.org/wiki/Pentecost#New_Testament
In Alaska, Divine Liturgy is celebrated in several Native Alaskan tongues, as well as English, Slavonic, and Russian (among others).
So which is it? There was a whole Jewish Septuagint long before the arrival of Christianity, or, the Jewish canon wasn’t fixed until after Christianity arrived (so they knew which books to include in the Septuagint)?
The original Septuagint was of the Five Books of Moses only, and easily predates subsequent unofficial translations of some Prophets and Writings. Where would one find a complete copy of the original Septuagint, whatever it was?