Isaiah 53:1 (King James Bible) who hath believed our report
The 1841 British edition introduced the reading who have. The subsequent LDS edition (1849) restored the original hath, the King James reading. For wh-questions in English, we expect either who hath (in the biblical style) or who has (in modern English), not who have. To be sure, who have does occur in the Book of Mormon text, but only as the head of relative clauses. For instance, the original text of the Book of Mormon has seven occurrences of the relative-clause use of who have, as in Mosiah 3:11: “those who have fallen by the transgression of Adam”. The current LDS and RLDS texts have many more examples of who have; again, all are in relative clauses. Most of these additional instances of who have are due to the editing of which have to who have. For further discussion of the editing of which to who, see under which in volume 3.
Summary: Maintain in Mosiah 14:1 the singular hath, the reading of the earliest Book of Mormon textual sources as well as the King James Bible for Isaiah 53:1.