Although the canonical Gospels were composed in Greek, there are indications that they drew from non-Greek sources. This makes sense since Jesus’ teaching was probably delivered in Hebrew/Aramaic, and according to early church traditions the earliest record of Jesus’ life was written in Hebrew/Aramaic.
One of the clues that the Synoptic Gospels descended from a Hebrew/Aramaic Life of Yeshua is the number of foreign words that were transliterated into Greek from either Hebrew or Aramaic (it is often impossible to distinguish Hebrew from Aramaic in Greek transliteration). Since modern translations of the Bible tend to hide these transliterated words, most readers are not aware of how many transliterated words there are in the Synoptic Gospels.
Certainly there is a wealth of Latin and Greek New Testament texts to consult and compare, however, within each family of texts and between the families of texts the variances and inconsistencies are staggering. The opposing ideas and readings these texts produce is overwhelming.
What is even more overwhelming is when we compare the Aramaic New Testament family to the Greek New Testament family. The Aramaic texts have a breathtaking accuracy spanning nearly 1800 years. Within the Eastern Aramaic family are 360 manuscripts, all beautifully written and consistent with each other. In hundreds of verses the Aramaic clearly shows itself to predate the Greek New Testament. In dozens of readings the Aramaic clearly shows how two different Greek readings were derived from an Aramaic original.
The Old Testament canon entered into Christian use in the Greek Septuagint translations and original books, and their differing lists of texts. In addition to the Septuagint, Christianity subsequently added various writings that would become the New Testament. Somewhat different lists of accepted works continued to develop in antiquity. In the 4th century a series of synods produced a list of texts equal to the 39, 46/51, 54, or 57-book canon of the Old Testament and to the 27-book canon of the New Testament that would be subsequently used up until today, most notably the Synod of Hippo in 393 CE. Also c. 400, Jerome produced a definitive Latin edition of the Bible (see Vulgate), the canon of which, at the insistence of the Pope, was in accord with the earlier Synods.
Thus, some claim that, from the 4th century, there existed unanimity in the West concerning the New Testament canon, and that, by the 5th century, the Eastern Church, with a few exceptions, had come to accept the Book of Revelation and thus had come into harmony on the matter of the canon. Nonetheless, full dogmatic articulations of the canon were not made until the Canon of Trent of 1546 for Roman Catholicism, the Gallic Confession of Faith of 1559 for Calvinism, the Thirty-Nine Articles of 1563 for the Church of England, and the Synod of Jerusalem of 1672 for the Greek Orthodox.