I have addressed the question as to whether the term “gospel” or “glad/good tidings” is an anachronism in the Book of Mormon at:
I have added some additional information from the Ugaritic Tablets (1350-1150 BC), pre-dating the Book of Mormon, showing that such a concept was known even before the time of Lehi et al. On the Ugaritic cognate to the Hebrew term בְּשֹׂרָה, Cyrus Gordon wrote:
535. bšr II ‘to get tidings (good or evil)’ (76:III:34, 35); D ‘to bring tidings’ (1 Aqht 86); bšrt (76:III:34) ‘tidings’ ; (51:V:88) tbšr bcl (89) bšrtk.yblt ‘be informed, O Bacl, I bring thy tidings’. (Cyrus H. Gordon, Ugaritic Textbook [Analecta Orientalia 38; Rome: Pontificium Institutum Biblicum, 1965], 377)
Here are Gordon’s transliteration of the relevant texts:
51:V:88
[88] gh.wtṣḥ.tbšr bcl
[89] bšrtk.yblt.ybn (Ibid., 172)
76:III:34, 35
[34] bšrt.il. bš[r b]cl
[35] w bšr.ḥtk.dgn (Ibid., 183)
1 Aqht 86
[86] abšrkm dn[ ] (Ibid., 245)
This is yet another nail in the coffin of the claim that “gospel” is an anachronistic word in the Book of Mormon.