Like Mormon ritual, much of Mormon theology remains relatively inaccessible to outsiders. The text of the Book of Mormon has always been spread to a broad audience, but the text is not a sufficient guide to understanding the details of Mormon teaching. Joseph Smith received extensive further revelation in the nature of sacred secrets to be shared with only a handful of close associates and initiates within the newly forming church.

The most famous such revelation was the doctrine of celestial  which was to say plural  marriage, revealed to Smith as early as 1833 but never publicized during his lifetime and formally announced to the world only in 1852, eight years after his death. And there were other doctrines of similar secrecy revealed to Smith, especially in the years just before his death. “God himself was once as we are now, and is an exalted man, and sits enthroned in yonder heavens! That is the great secret,” he is reported to have said in one of his last communications with his followers.

The connections between the sacred and the secret in early Mormonism did not come out of nowhere. Believers, of course, consider the source to be divine inspiration  although over the course of the last century Mormon teaching has moved away from many of Smith’s more radical ideas, which are often not accepted by contemporary LDS members. Academic students of early Mormonism have traced the mysteries expounded by Smith to the hermetic tradition of secret magic dating back to the Renaissance and beyond. If this account is accurate, then Mormonism’s theological secrets actually have more than a little in common with religious mysteries that can be found in medieval Islamic esotericism, kabbalistic mysticism and ancient Christian Gnosticism. Successive generations have rediscovered these secrets and reasserted their antiquity in ways very similar to Smith’s discovery of ancient tablets. For example, the most important work of the kabbalah, the Zohar, presents itself as a lost manuscript written by the 2nd-century mystic Rabbi Shimon bar Yohai, though scholars maintain that it was composed in the 13th century by the man who “discovered” it.

The greatest difference between the esoteric tradition and Smith’s version of it is that Smith’s faith has grown into an organized religion rather than remaining the preserve of a select few. Almost from the start of his career, Smith was denounced as a charlatan, an impostor and worse. Such criticisms sometimes pointed to his early pre-revelation career as a treasure seeker who used techniques like the seer stone (similar in function to a crystal ball) and the divining rod to seek treasure in the countryside of upstate New York. Notwithstanding these attacks, Mormonism grew steadily. Growth brought publicity  and with it came not merely prejudice but outright persecution. This external persecution created a second, externally driven source for secrecy: protection.

Not content with polemics, Mormonism’s opponents turned to violence. In 1838, after skirmishes between armed Mormons and state militia left several people dead, Gov. Lilburn Boggs of Missouri issued a military order declaring that the Mormons had made open war on the state and that therefore they “must be treated as enemies, and must be exterminated or driven from the state, if necessary, for the public good.” Later, at Nauvoo, Ill., the Mormon community under Smith’s leadership came under constant pressure from skeptical and sometimes violent neighbors. In response, Smith sought and received a measure of home rule for Nauvoo, including the authority to establish his own municipal militia. Though the militia grew until it was a substantial fighting force, Smith was nevertheless gunned down by a kind of quasi-organized lynch mob after having been arrested and jailed in nearby Carthage.

Unhindered by Smith’s death, the Mormons, now under the leadership of Brigham Young, went out to Utah to establish their own kingdom. In what felt like the relative safety of the intermountain West, Mormons began to practice plural marriage in the open  and ended up paying dearly for this lapse in secrecy. In 1856 the Republican Party made the defeat of polygamy a key plank in its first national platform, characterizing it alongside slavery as one of the “twin relics of barbarism.” The federal government soon criminalized the practice and then in effect outlawed membership in the Mormon Church until it would agree to give up polygamy. The Mormons appealed this persecution to the Supreme Court, which turned them down flat, holding that religious belief was protected by the First Amendment but that religious conduct was not. After the Civil War, federal prosecutors in the Utah territory and in neighboring areas convicted and jailed thousands of Mormons in the most coordinated campaign of religious repression in U.S. history.

The reaction of the Mormon Church to this new wave of persecution was, initially, to take refuge in secrecy once again. In 1890, the president of the church, Wilford Woodruff, issued a manifesto in which he gave his “advice” to members of the Mormon Church not to enter into any marital relationships that would violate the laws of the land. Publicly this declaration had its desired effect of placating the federal government; in 1896, Utah was allowed to become a state. But like Jewish rituals under the Spanish Inquisition, plural marriage continued, secretly in Utah and also among refugees (like several of Mitt Romney’s ancestors), who fled to Mexico or other places the law could not reach.