Sad to see an irresponsible critic of the Church pushing the easily debunked theory that a General Authority, B.H. Roberts, lost his testimony due to the overwhelming problems in the Book of Mormon. Ridiculous. B.H. Roberts did examine the leading evidences against the Book of Mormon. Those issues, frankly, were much more challenging in 1922 than they are today as some former weaknesses have become strengths through further discovery and learning, and as some problems have been resolved by better understanding what the text actually say. But to help Church leaders understand the arguments that could be waged against the Book of Mormon, he wrote what might be considered a version of a lawyer's brief detailing what one's adversary might argue. He was frank and open in doing this. But this exercise certainly did not wither his testimony of the Book of Mormon. He remained a firm advocate for the Restoration and the divine power of the Book of Mormon. For evidence about the nature of his work and the strength of his testimony afterwards, see these resources:

 "From The Truth, The Way, and the Life: The Truth About the Way B.H. Roberts Viewed the Book of Mormon at the End of His Life," a 2015 post here at Mormanity.

"Evasive Ignorance: Anti-Mormon Claims that B.H. Roberts Lost His Testimony"  by McKay V. Jones at FairMormon.org. 

"B. H. Roberts and the Book of Mormon: Exhumation and Reburial" by Stephen Smoot, Ploni Almoni, Aug. 11, 2020.  (Also see his addendum to the B.R. Roberts post where he addresses a radio broadcast used to suggest Roberts was vacillating in his faith.) Here is the interesting conclusion from Smoot's valuable contribution:

The burden of proof now rests on those who wish to portray B. H. Roberts as a closeted unbeliever.⁵⁴ The published and publicly spoken words of Roberts from 1922 to the time of his death in 1933 are emphatically not the whimpering of a distraught, unsure man racked with doubt. To be sure, Roberts privately expressed frustrations that he felt “stumped” with the Book of Mormon “difficulties” he encountered in his studies and that his concerns were met with either indifference or silence from Church authorities.⁵⁵ But this is not the same as Roberts being a closet doubter. Not by a long shot. “Roberts’s deeply ingrained commitment to scholarship made him a ‘disciple of the second sort’ who was always open to new information and willing at least to entertain new ideas and suggestions,” observes Allen.⁵⁶ “This did not mean that Book of Mormon ‘problems’ convinced him that the book was not what Joseph Smith said it was. It only meant that he was willing to look at every possible challenge while maintaining his long-time convictions.”⁵⁷

At this point, let me take a moment to point out what should now be obvious. Despite John Dehlin’s best efforts to gaslight his audience, B. H. Roberts is not some ex-Mormon role model. Not only is there is no evidence that Roberts lost his faith in Joseph Smith or the restored Church of Jesus Christ, there is, as we’ve seen above, in fact abundant evidence to the contrary. After 1922 and 1927, Roberts repeatedly and publicly declared his testimony and argued for the inspiration and authenticity of Joseph Smith’s scriptural texts. So if Roberts did secretly lose his faith in 1922 or 1927, he lied about it and continued to publicly advocate for the divinity and historicity of the Book of Mormon, the prophetic calling of Joseph Smith, and the inspiration of the theology of The Church of Jesus Christ of Latter-day Saints. He was, in this scenario, intellectually dishonest to the highest degree. Perhaps he was, as Dehlin ludicrously tried to claim about another eminent Latter-day Saint historian, merely in it for a paycheck and the social clout. After all, Roberts’ books continued to sell well during his lifetime and he remained a General Authority until his death. Perhaps after losing his faith pure avarice and narcissistic vanity motivated Roberts to continue writing and speaking positively for the claims of Joseph Smith. But is that the kind of person ex-Mormons want to gleefully claim as one of their champions and role models? Such a person is not a bold, brave truth-teller, but rather an intellectually bankrupt, morally decrepit impostor.

There is a much more parsimonious explanation for all this that does not require the absurd contrivances of barely literate podcasting hucksters. That explanation is that Brigham Henry Roberts was a faithful, committed Latter-day Saint throughout his life. He was not, as Brigham D. Madsen and other members of the mid-twentieth century Mormon intelligentsia have tried to portray him as, an Elias for the type of pseudo-Mormon historiographical and theological naturalism and skepticism that pervaded their own thinking. And he certainly was not, as Dehlin has tried to claim, “a high-level Mormon General Authority [who] lost his faith in the historicity of the Book of Mormon.” To suppose Roberts was some kind of proto-Redditor who would have found an intellectual home among the likes of John Dehlin or Jeremy Runnells is the absolute pinnacle of nonsense. 

As shocking as this might sound to bigots who suppose members of The Church of Jesus Christ of Latter-day Saints are nothing but unmindful, unthinking, uneducated, uncritical, and unaware simpletons, there has, in fact, been a rich intellectual tradition in the Church, with many Latter-day Saints who have asked hard questions while also remaining committed to their faith.

B. H. Roberts was one of them.

Smoot is responding to John Dehlin's recent podcasts featuring an "amazing" work of scholarship, a 2019 master's thesis from Shannon Caldwell Montez entitled "The Secret Mormon Meetings of 1922." You can read this online at https://scholarworks.unr.edu/bitstream/handle/11714/6712/Montez_unr_0139M_13054.pdf. As you read it, ask yourself how the author handles the numerous speeches given by Roberts, his many articles, and his several books, especially The Truth, the Way, the Life, the masterpiece he published long after his exercise in Book of Mormon problems, that affirm his conviction that the Book of Mormon is historical, and divine. It's the kind of question that Dehlin ought to have asked as well. But if I'm not mistaken, you won't find much awareness of Roberts's clear positions on the Book of Mormon in Montez's thesis, because such works are not listed in her bibliography. Here is the portion of the bibliography that shows all the sources whose last names begin with the letter "r":

It is simply irresponsible to pretend to tell us what Roberts thought without paying any attention to what he told us over and over in clear and powerful terms in primary sources. His great masterpiece cannot be ignored if we wish to know what he thought. It was clear that he had a powerful testimony of the divine nature of the Book of Mormon and of the Restoration. 

Other resources to consider:

• McKay V. Jones, "Evasive Ignorance: Anti-Mormon Claims that B.H. Roberts Lost His Testimony," FairMormon.org.