Comments from a BYU professor stir up a troubling past.

“God has always been discriminatory.” So says Randy Bott, a professor of religion at Brigham Young University, in a Washington Post piece by Jason Horowitz. Bott’s statements have kicked up the most significant dust storm concerning Mormonism and race in 30 years. Bott was quoted at length in Horowitz’s piece, which was published on Tuesday. (Slate is owned by the Washington Post Co.) By Tuesday night, BYU students were planning protests concerning Bott’s comments, ABC4’s 10 o’clock news in Salt Lake City had cut off coverage of Mitt Romney’s primary sweep to report on those comments, and BYU administrators—not to mention members of the LDS Church’s hierarchy—had huddled together, trying to come up with an appropriate response.

Bott’s comments—about which more below—were incendiary. But they wouldn’t have any significance were it not for the LDS Church’s complicated and troubling history with regard to race, a history that many Mormons might have hoped was safely in the past.

Starting shortly after the death of the church’s founder, Joseph Smith, in 1844, the Mormon Church began denying its priesthood—otherwise granted to faithful young men over the age of 12 more or less as a matter of course—to men of African descent. That policy survived for well over a century. Only with a divine revelation announced by then-prophet Spencer W. Kimball in 1978 did the church finally overturn the ban and allow “all worthy males,” regardless of race, full and equal membership in the religion.

Why did the church withhold the priesthood from blacks for over a century? Among the reasons trotted out by church leaders—including church presidents—during that time: Black people are the cursed descendants of ancient Biblical figures; black people committed pre-mortal perfidy; black people lacked the intelligence and personal integrity to hold such a sacred office.

Such past beliefs have never officially been repudiated. And the failure of the church to repudiate them helped set the stage for the comments made by Bott, perhaps the most popular professor at BYU (and at one point, according to ratemyprofessors.com, the most popular professor in the country). Bott, 67, teaches in the school’s religion education department, which is more like a college-level seminary class than the standard “religious studies” program at a liberal arts college. In his comments to the Post, Bott cited the Old Testament anti-heroes Cain and Canaan, whom Christians of many denominations long believed to be cursed for their ancient transgressions, marking their offspring with dark skin and casting them into perpetual servitude of the lighter skinned races.

The Mormon Church’s own longstanding priesthood ban was, according to Bott, not racist. Rather, it was a “blessing.” Prior to 1978, blacks weren’t spiritually mature enough to be ordained with such authority. Bott compared blacks to “a young child prematurely asking for the keys to her father’s car,” and told Horowitz that misusing priesthood authority—like crashing dad’s Oldsmobile—could have put blacks “in the lowest rungs of hell,” reserved for serial killers, child rapists, world-class tyrants, and “people who abuse their priesthood powers.”

On Wednesday, Bott apologized to his students for the uproar. He also claimed that he had been misquoted. Yet he provided similar justification for the priesthood ban in a blog post from 2008 that was only taken down after this week’s story broke.

For many Mormons, reading Bott’s words was like unearthing a theological dinosaur long thought extinct but suddenly rediscovered in the corner of an obscure BYU office. His positions seem radically out of place in a modern church with an international membership that includes probably some 500,000 Mormons of African descent. The church’s expensive and ubiquitous “I’m a Mormon” public relations campaign has been carefully and deliberately multiethnic; Mormon leaders want the world to view the religion as the diverse global community it has become.

Unfortunately, Bott’s beliefs, though arcane, represent a strain of Mormonism that has persisted well past the 1978 revelation. For most of the 182-year lifespan of the LDS Church, members of the church hierarchy—the senior-most of which are called prophets and speak to and for God—used similar racist rationalizations for excluding blacks from full membership. Joseph Fielding Smith, who served as church president in the early 1970s (and was the great-nephew of the religion’s founding prophet), wrote a popular treatise, still available on Kindle, asserting that during a pre-mortal battle between God and the devil, blacks were “fence-sitters,” siding neither with God or Lucifer. According to Fielding Smith, when blacks came to Earth, God cursed them with dark skin to set them apart from the more courageous whites who had sided with God.

Rather than explicitly denouncing such racialist theology, the LDS Church has insisted that Kimball’s 1978 revelation, known as Official Declaration 2, stands on its own, hoping that time—and the church’s humanitarian and missionary efforts in Africa and around the world—would help to bury its racist past. Bott’s comments only highlight how this strategy has failed. The 1978 revelation itself does not address why the ban was instituted in the first place, and the lack of answers from today’s Mormon leaders creates a theological vacuum. To fill this vacuum, Mormons turn to the reams of answers provided by past prophets, who led a church in which blacks were not welcome.