“All Scripture is breathed out by God and is profitable for teaching, for reproof, for correcting, for training in righteousness, so that the man of God may be proficient, fully equipped for every good work” (2 Timothy 3:16-17 Mounce).
The New Testament Scriptures can trace their recorded lineage back to ancient handwritten copies of the original documents. However, this may raise a concern in regard to these Biblical records, since a copy is rarely as good as an original. With this in mind, there are some important things to remember when it comes to the reliability of these Scriptural texts.
To begin, we should note that the New Testament writings were all produced within a period of about sixty-five years during the mid to late first century. While sixty-five years may sound like a long time, it is actually a very brief period in the context of ancient literature. Although some sources dispute that timeline, it is generally agreed that there was a relatively short interval between the original New Testament documents and the handwritten copies that followed. This is important because this limited timeframe offers less opportunity for mistakes and errors to creep into each reproduction.
This leads us to the next item for our consideration: the preservation of these New Testament documents.
Many New Testament copies were originally written on papyrus, a paper-like material that was made from a marshy plant. Papyrus-based paper was relatively inexpensive but not very durable. However, some papyrus fragments have been discovered with portions of Biblical text that date back to the second century A.D. One such fragment was found in Egypt, thus indicating that the New Testament documents had entered into wide circulation during that period.
Another ancient writing material was called vellum or parchment. Vellum was made by processing animal skins into a medium that was suitable for writing. Vellum was more durable than papyrus and served as the writing material that was used to produce many of the ancient New Testament manuscripts we have today. There are more than 20,000 of these ancient documents that remain in existence. This includes complete manuscripts and portions of other New Testament books.
These comprise over 5000 copies of the New Testament written in Greek, 10,000 copies written in Latin, and over 8000 copies written in other languages. Taken together, the wealth of manuscript evidence for the Biblical Scriptures is greater than that of any other piece of ancient literature. This enables scholars to reproduce the original documents with great accuracy and promotes confidence in the reliability of the New Testament.
Additional information: See Norman Geisler, The Dating of the New Testament https://www.bethinking.org/bible/the-dating-of-the-new-testament