I appreciated something that Bart Ehrman said on pages 98-99 of The Orthodox Corruption of Scripture: The Effect of Early Christological Controversies on the Text of the New Testament:
"I
have observed that the anti-adoptionist changes of the text occur
sporadically throughout the tradition, not at all with the kind of
consistency for which one might have hoped. Given the character of our
evidence, however, the uneven distribution and irregular attestation are
not surprising. The scribes of our surviving manuscripts more commonly
preserved theological variations than created them, and none
of these scribes appears to have made a concerted effort to adopt such
readings with rigorous consistency. Almost certainly there was no
attempt to create an anti-adoptionistic recension of the New Testament.
Indeed, the Christians of the proto-orthodox camp did not, on one
level, need to change their texts; they believed that the
texts, in whatever form they came, already attested their christological
views. Most of the debates over Christology, then, centered on the
correct interpretation of the texts rather than on their
wording. But to some degree the debates did impact the physical
dimensions of the manuscripts, as scribes periodically----if not
rigorously----modified the words of the New Testament to make them more
serviceable for the orthodox cause, effecting thereby the orthodox
corruption of Scripture."
Ehrman's overall argument in this book
is that proto-orthodox Christian scribes in some cases altered the text
of New Testament writings to conform passages to proto-orthodox ideas.
That may sound to some people like a conspiracy theory. Some may even
conclude that Ehrman is arguing that we can't trust the New Testament in
our Bibles because we don't have the original text with us, and
subsequent copies reflect alterations designed to serve the cause of the
proto-orthodox in Christological debates.
Well, I've not read
everything that Ehrman has ever written, so I don't know offhand how
extreme he gets. But what he says on pages 98-99 of The Orthodox Corruption of Scripture
strikes me as quite reasonable and level-headed. In that passage, I
don't see some large-scale conspiracy to make the entire New Testament
conform to proto-orthodoxy, as if certain ideas in the originals have
been completely suppressed. I also don't see a hyper-skepticism about
scholars' ability to make conclusions about what the original text may
have said. Rather, what Ehrman is suggesting is that there were cases
in which scribes altered the text----adding a word here, taking away a
word there, changing this little phrase----out of a concern that a given
passage was problematic for proto-orthodoxy. They weren't taking a
sledge-hammer to the text and undertaking massive reconstruction of it.
Actually, Ehrman acknowledges that the scribes were quite conservative
in terms of their copying and transmission of the text, and so there
were readings that they preserved that were arguably problematic in
terms of proto-orthodox positions (though the scribes may not have seen
them as overly problematic). But Ehrman's point is that, on some
occasions, scribes changed the wording of the text----changing a text
that said that Joseph was Jesus' father, making the text explicitly say
that Jesus was God, etc. I agree with Ehrman that this occurred.
(UPDATE: Later in the book, however, Ehrman discusses what he considers to be larger interpolations of verses or units.)
Does
that mean that the New Testament originally did not contain a belief in
Jesus' divinity, until later scribes came along and conformed the text
to that doctrine? I can't make that blanket statement, and my
impression is that Ehrman does not believe that, as well. Ehrman seems
to acknowledge that the Gospel of John has a high Christology, although
he does not appear to think that the same can be said for (say) the
Gospel of Luke.