In his book, Breaking the Mormon Code, Matthew A. Paulson asked the following question:
How can
Mormons seriously believe that the Bible is authoritative when they are told
that plain and precious parts have been removed. (Matthew A. Paulson, Breaking
the Mormon Code: A Critique of Mormon Scholarship Regarding Classical Christian
Theology and the Book of Mormon [Livermore, Calif.: WingSpan Press, 2006,
2009], 134, italics in original)
As with many Protestants, Paulson confuses “sufficiency” (as
a Reformed Protestant, he would hold to formal sufficiency of the 66 books of
the Protestant canon) with something being “authoritative.” A document can be
authoritative without being materially, let alone formally, sufficient and/or
being 100% textually pure.
An analogy would be the authority of the Bible before the inscripturation
of the 27 books of the New Testament. It was authoritative (cf. 2 Tim 3:15, for
e.g.,) but it was not sufficient. Even John Calvin recognized this in his
commentary to 2 Tim 3:17:
But here an
objection arises. Seeing that Paul speaks of the Scriptures, which is the name
given to the Old Testament, how does he say that it makes a man thoroughly
perfect? for, if it be so, what was afterwards added by the apostles may be
thought superfluous. I reply, so far as relates to the substance, nothing has
been added; for the writings of the apostles contain nothing else than a simple
and natural explanation of the Law and the Prophets, together with a
manifestation of the things expressed in them. This eulogium, therefore, is not
inappropriately bestowed on the Scriptures by Paul; and, seeing that its
instruction is now rendered more full and clear by the addition of the Gospel,
what can be said but that we ought assuredly to hope that the usefulness, of
which Paul speaks, will be much more displayed, if we are willing to make trial
and receive it?
Further Reading:
Not
By Scripture Alone: A Latter-day Saint Refutation of Sola Scriptura
Listing of articles responding to "Breaking the Mormon Code"