Do references to lost writings prove scripture was suppressed?

Paul refers to an earlier letter or communication and restates the instruction he meant in verses 10–11. That supports missing correspondence, but does not establish that it was intended as canonical Scripture or was suppressed.

You acknowledge the lost correspondence without assuming its inspiration, contents, or cause of disappearance.

Yes. Any letter from an apostle was automatically scripture, so its absence proves deliberate removal.

The verse identifies a prior communication, but does not say it was a canonical writing or explain why it is not extant.

Eusebius distinguishes accepted, disputed, and rejected writings. Athanasius lists the books he regards as canonical and separately names books suitable for reading. Together they show active classification and differing reception; they do not document a campaign to remove inspired books.

You distinguish questions about a book’s reception and status from evidence of deliberate suppression.

They prove the fourth-century church had one universally agreed canon and that every omitted work was uninspired.

Eusebius explicitly records disputed books and differing views; one bishop’s list cannot establish universal agreement or the inspiration status of every missing work.

First Nephi 13 describes plain and precious things taken from the record, and the ninth Article of Faith says God “will yet reveal many great and important things.” These express LDS beliefs about loss and continuing revelation; evidence for a specific missing New Testament text or its removal is a separate historical question.

You state the LDS claims accurately while separating belief from independently documented evidence about particular books.

The Church’s open canon proves that we know which books were removed and who removed them.

Open canon and the vision in 1 Nephi 13 do not identify a specific missing Pauline letter or document its transmission history.

A Protestant can argue that the apostolic witness is foundational and that Scripture equips believers for every good work; the Westminster Confession sets out the resulting canon and sufficiency doctrine. To establish closure, the argument still needs to show why those premises exclude further canonical revelation and how the final book list is warranted.

You present the case through its strongest theological premises and identify the additional historical and interpretive steps instead of treating a single verse as self-proving.

The Bible never says “the canon is closed,” so Protestant sufficiency has no biblical argument.

That dismisses the positive case. Engage the claims about apostolic foundation and scriptural sufficiency, then examine whether they entail a closed canon.