If the Bible is the most accurate historical text, and doesn’t have any direct proof against it, then what makes the Old and New Testament only 99% accurate and not 100% accurate?
The original writings of the New Testament authors (known as the “autographs” to scholars) are perfect and inspired. These letters were copied many times over several generations before the oldest copies of the letters were produced which we have available to us. The oldest manuscript which has been dated with confidence is the Rylands Papyrus, in the Rylands library in Manchester, which was written about AD 125–fifty years or so after the original. However, this is a rather small fragment. We have several manuscripts from the second century, including the Washington Manuscript and the Bodmer Papyri. However, these, too,are fragments. We have entire New Testament letters from the third century and entire New Testaments from the early fourth century. By the fourth century, a number of copying errors had entered into the Greek manuscripts. The vast majority of these copying errors are things like spelling errors, a single word lost, two words juxtaposed, lines missed and the like. Because we have thousands of manuscripts, and dozens from the first four centuries, scholars can easily correct the vast majority of these copying errors. With that said, there are a few copying errors which are difficult to resolve. Let me give you one example. In Luke 17:35 Jesus says, “But wisdom is proved right by all her children.” Some of the oldest manuscripts have “But wisdom is proved right by all her deeds.” Which is the original? Because the parallel verse in Matthew 11:9 has “But wisdom is proved right by all her deeds” scholars presume that an early copier tried to “improve” Luke 7:35 by harmonizing it with Matthew 11:9. We are pretty sure what the original was, but there is some doubt. There are a number of other examples. I deal with this in a chapter of my book “Reasons for Belief” (available at www.ipibooks.com), as well as with several Q & As at the web site. The bottom line is that we are virtually certain about roughly 99% of the Greek New Testament (scholars debate this number, but this is a conservative estimate). The remaining 1% involves either difference of no significant consequence and/or of no doctrinal or theological importance. We can be very confident about the reliability of our Greek New Testament, but we cannot claim that it is absolutely, 100% precisely the same as the original.
By the way, even the harshest critics of the reliability of the New Testament will agree that the historical reliability of the New Testament does not depend on the 1% of uncertain text. The historical reliability of the New Testament is a separate question. I also deal with this question in the book Reasons for Belief mentioned above.