Isaiah 53:12 (King James Bible) and he bare the sin of many
As discussed under Mosiah 14:6, the use of the plural sins here in verse 12 is consistent with usage elsewhere in Mosiah 14 and therefore appears to be intended; the plural number is supported by the Greek Septuagint translation of Isaiah 53:12. Later on in Mosiah 15, Abinadi refers once more to this verse from Isaiah 53, and as before he uses the plural sins:
Generally speaking, the Book of Mormon text uses the plural sins in referring to Christ’s taking away the sins of the world. For discussion, see under 1 Nephi 10:10.
Summary: Maintain the plural usage in Mosiah 14:12 (“and he bare the sins of many”).