Copied by hand
Before printing, every book was copied by hand. Copies wore out, burned or rotted, and most ancient books simply disappeared. For the ones that survive, the question is how many copies made it, and how early they are.
For the New Testament, the numbers are huge:
More than 5,800 handwritten Greek copies of the New Testament have been catalogued. There are over 20,000 more in other languages, about half of them in Latin.
Some are whole Bibles. Many are single books or fragments. Together, they let scholars check every line of the New Testament against thousands of independent witnesses.
The oldest scrap
In 1920, a scholar named Bernard Grenfell bought a batch of papyrus fragments in Egypt. One of them, about the size of a credit card, went to the John Rylands Library in Manchester, and was only identified years later.
When it was finally studied, it turned out to be a page from the Gospel of John. On one side, John 18:31 to 33. On the other, John 18:37 to 38. Jesus standing before Pilate.
Scholars date it to the second century. Within a few generations of the apostles, John's Gospel was already being copied and read in Egypt.
How other ancient books compare
Set the New Testament beside the great books of Greece and Rome:
The New Testament scholar Daniel Wallace puts it simply. "The average classical author's literary remains number no more than twenty copies."
Two copies
The Annals of Tacitus is the great history of the early Roman emperors. The first six books survive in one manuscript, copied around AD 850. The rest survive in another single manuscript, copied in the eleventh century at Monte Cassino.
That second manuscript holds the passage where Tacitus records that Christus "suffered the extreme penalty during the reign of Tiberius at the hands of one of our procurators, Pontius Pilatus."
One copy, made nearly a thousand years after Tacitus wrote, and historians treat it as solid. The New Testament has thousands, starting within a century or so of the originals.
Why this is a big deal
If any book from the ancient world can be trusted to say what its authors wrote, it's the New Testament. Nothing else is even close.
Jesus said it would last: "Heaven and earth shall pass away, but my words shall not pass away" (Matthew 24:35). Two thousand years of copying, and his words are still here, checked against more witnesses than any other book of their age.