When the thousands of copies of manuscripts (far more than for any other document of antiquity) are compared, we can know that the New Testament is 99.5% textually pure. In the entire text of 20,000 lines, only 40 lines are in doubt (about 400 words), and none affects any significant doctrine.
{2}
Even if all the manuscripts in the whole world were to disappear, the New Testament is so comprehensively quoted by early church letters, essays and other extra-biblical sources that we could still reconstruct almost the entire testament.
We have a much fuller explanation of this in our article “Are the Biblical Documents Reliable?” at
www.probe.org/are-the-biblical-documents-reliable