This series was first motivated by the far too many members I heard – including missionaries – express the opinion that they didn’t need to read the Old Testament. Every now and then, this opinion was couched as saying they didn’t need to, because they could read the Book of Mormon. This of course is a false dilemma.
It also represents a massive misunderstanding of the relationship the Book of Mormon has with the Old Testament. In short, while the Book of Mormon is one of the greatest aides to understanding the Bible, including the Old Testament, the reverse is also true. To neglect (or worse, to refuse to read) the Old Testament means to miss out on what some of the Book of Mormon is trying to say.
Critics have advanced the opinion that the Church of Jesus Christ of Latter-day Saints has replaced the Bible or devalues it because of the Book of Mormon. That’s no excuse for members to adopt those ideas too; preferably we should take our theological hints from more legitimate sources. Others perhaps take the Book of Mormon’s statement that “plain and precious things” have been taken from the Bible to mean that they are unreliable, but this is a mistake. Firstly, it should be noted those plain and precious things were removed after the Bible passed into the hands of the Gentiles, so if anything, if stuff is missing it is missing from the New Testament (1 Nephi 13:25-28). Secondly, it does not say that what is left is unreliable; indeed one of the major purposes of the Book of Mormon is to show that the Bible is true (Mormon 7:9).
If parts of the pre-Christian Book of Mormon are plainer on some topics that’s not because of tampering in the Old Testament, but because the Nephites are “highly favoured” as exiles so that, as Alma states, things were “made known unto us in plain terms, that we may understand” (Alma 13:23). That the Old Testament is hard to understand on some topics is not the direct result of human action but ultimately God’s doing, for “for God hath taken away his plainness from them, and delivered unto them many things which they cannot understand, because they desired it”. (Jacob 4:14) Yet just because it is hard to understand does not make it valuable, for those parts which are hard to understand “are plain unto all those that are filled with the spirit of prophecy” (2 Nephi 25:4), the Book of Mormon is quite clear about the dangers of rejecting any part of scripture (2 Nephi 28:29-30), and the Book of Mormon itself asserts the ultimate interdependence of itself and the Bible, that the two will “grow together, unto the confounding of false doctrines and laying down of contentions, and establishing peace among the fruit of thy loins, and bringing them to the knowledge of their fathers in the latter days, and also to the knowledge of my covenants, saith the Lord” (2 Nephi 3:12).
And you see this as you read it. Reading the Bible helps us understand the Book of Mormon, and reading the Book of Mormon helps us understand the Bible. The narrative of the Book of Mormon leaps into action in the first year of the reign of King Zedekiah, assuming you know who that is and why Jerusalem, Israel and the Prophets are all that important (1 Nephi 1:4). It frequently quotes and comments on biblical passages at length (e.g. 1 Nephi 20-21//Isaiah 48-49, Mosiah 14//Isaiah 53, and many others – 26 chapters worth!), both giving insight and highlighting many of those passages of most importance to us today. When teaching, Nephi, Lehi, Alma and others make frequent allusions and references to biblical events (the Exodus in 1 Nephi 17, the fall in 2 Nephi 2, Melchizedek in Alma 13 and many many others), and if you’re not familiar with these, you are going to miss something. Likewise a reader unfamiliar with the Old Testament is going to miss all the times they are drawn upon and interwoven into the text, and miss things like the allusions to Isaiah 29 in 1 Nephi 22, or Isaiah 5:1-4 in Jacob 5. The Book of Mormon even specifically mentions that it is leaving stuff out because they’re in the Old Testament (Ether 1:3-4); someone who refuses to touch the Old Testament simply isn’t going to know what the Book of Mormon expects them to know. I don’t imagine that, when the authors meet us on judgment day (2 Nephi 33:11, Moroni 10:27), they will be too impressed if we claim their book as a reason that we failed to read writings that they loved and expected us to read.