The Septuagint (LXX) is a translation of the Hebrew scriptures and was made for the Jewish community, not Christians. The vocabulary is Greek and the syntax Hebrew. There is a Semitic influence in the vocabulary of the LXX. The New Testament is not a translation and is written for Christians who have the ransom sacrifice of Jesus Christ. Third, The Greek of the NT is 180 years to 310 years removed from the Greek of the Septuagint.