Origins of the Bible

The Bible is the best attested ancient literature in the world. Copies of the Bible date to the time of Christ or 100 years before Christ. The Bible of the early Christians, the Septuagint was written in 280BC under the patronage of Ptolemy of the Seleciud empire. The Qumran or Dead Sea scrolls, mostly in Hebrew and contained fragments of almost every book of the Hebrew Bible (later Christian OT). Scrolls of the book of Isaiah, Deuteronomy and Daniel were intact. When one compares with the Masoretic text of the Leningrad scroll of early 11th century AD, the two most ancient copies of the Hebrew Bibles are almost identical in content though slight variants exist. This is remarkable considering more than 1,000 years separates the DSS and the MT. It tells the incredible precision in copying of the scribes at work making sure the biblical text word by word remains exactly as it is written in the beginning. The Greek New Testament as it was more recent comparatively speaking, is even better attested.
You have more than 5,000 whole or fragments of each of the NT book or letter. From the early 2nd century text of a sentence in John's Gospel to late Byzantine period, we have a host of NT books, some in a collection as a complete Bible, both OT and NT in Greek like the famous Codex Sinaiticus (4th century) and Codex Alexandrinus (early 5th century). Many more like codices Vaticanus and Bezae, each had made its name in the luminary of biblical texts. As copying became widespread during the early centuries of the Christian expansion in the Roman world, more and more copies of New Testament texts were produced. By early 2nd century we have evidence of the codex instead of the usual scrolls of the books of the Hebrew Bible. Soon we have the four gospels compiled as one codex and sometimes the Acts of the Apostles is added to the fourfold gospels. Likewise Paul's letters gained popularity in early Christianity and demand for copies of paul's letters must be high as there are numerous codices of Paul's 13 or 14 letters collated and compiled together. The 14th epistle of Paul is presumably the letter to the Hebrews. As the 3rd and 4th century came along, the complete NT canon became a phenomenon, whole NT codex is now found to contain all 27 NT books. That led to Christian emperors decreeing that alongside the Greek OT, the Septuagint, which early Church Father's deemed to be Christian Scripture, the NT books are now added to the LXX making a complete Bible as we know today. As an aside the LXX has a number of extra canonical books valued highly by the early church and hence, books like Ben Sira and Shepherd of Hermas were included in Codex Sinaiticus, for instance.