Hundreds of years of careful scholarship have shown that the Bible documents are authentic, accurate, and reliable. Old Testament manuscripts exist today dating from as far back as 250 B.C., with the Dead Sea Scrolls discovered in 1947.
The quantity of New Testament manuscripts is unparalleled in ancient literature. There are over 5,000 Greek manuscripts, about 8,000 Latin manuscripts, and another 1,000 manuscripts in other languages (Syriac, Coptic, etc.). In addition to this extraordinary number, there are tens of thousands of citations of New Testament passages by the early church fathers.
In contrast, the typical number of existing manuscript copies for any of the works of the Greek and Latin authors, such as Plato, Aristotle, Caesar, or Tacitus, ranges from one to 20.
The time span for most of the New Testament is less than 200 years from the date of authorship to the date of our earliest manuscripts (some within 100 years). This can be sharply contrasted with the average gap of over 1,000 years between the composition and the earliest copy of the writings of other ancient authors.
This reliability can best be understood by looking at other documents we have that were written by historical figures. For example, if you look at someone as famous as the Roman emperor, Julius Caesar, we have only 10 documents (reconstructed) written by Caesar, and the time span between the document and his life is about 950 years.
Archaeological discoveries in the Middle East have also supported what the Bible describes. Because the historical narratives of the Bible are so specific, many of its details are open to archaeological investigation. Higher criticism in the nineteenth century made many damaging claims that would completely overthrow the integrity of the Bible, but the explosion of archaeological knowledge in the twentieth century reversed almost all of these claims.
Source: Bible Companion Handbook*, Kenneth Boa