Link. A good overview over NT manuscripts, a somewhat less good overview over doctrine

Ken Boa : How Accurate Is the Bible?
https://kenboa.org/apologetics/how-accurate-is-the-bible/

Ken Boa makes a page with textual history on NT writings, perhaps especially Gospels.

However, in the intro, he makes a blunder:

Consider the following statements:

• The Bible says that God helps those who help themselves.
• The books of the New Testament were written centuries after the events they describe.
• “Cleanliness is next to godliness” is in the Bible.
• According to the Bible, the earth is flat.
• The earliest New Testament manuscripts go back only to the fourth or fifth centuries AD.
• The Bible teaches that the earth is the center of the universe.
• The English Bible is a translation of a translation of a translation (etc.) of the original, and fresh errors were introduced in each stage of the process.

How many of the above statements do you think are true? The answer is none; all of them are false. Yet these false impressions persist in the minds of many, and misinformation like this produces a skeptical attitude toward the Bible.

It is true that the Bible does not say the Earth is flat. However, it is also true it includes a few statements which might lead an unaware reader to conclude it does. 4 corners in at least one location of the Bible means specific locations, not points of the compass, so what about that? Well, the Hebrew word for earth can also mean land. And the main landmasses do show like a Riemann rectangle with some holes in it on the hemisphere opposite the Pacific.

However, it is hard to escape the conclusion the Bible says the Earth stands still or that Sun and Moon have daily movements, that were arrested for a full "day" (12 hours? 24 hours?) when Joshua fought a battle. Or that Heaven (religious sense) is very arguably a place above the stars, so that the space in which stars are cannot be infinite, but must be limited, and therefore also have a centre.

As for "New Testament manuscripts", it is possible that manuscripts of all 27 books (or of wholes Bibles overall) go back to only 4th or 5th centuries, but this is probably due to the codex book form only then getting large enough for that, and Ken Boa talks of what can be expected from papyri : single book manuscripts.

But it is worthwhile he gives a very good overview, I think./HGL