A central claim of Noah Feldman's Sunday Times magazine essay on Mormonism is that Mormons have had to be secretive about the precise content of their faith in order to avoid persecution: "If 19th-century Mormon secrecy was a matter of survival, 20th-century Mormon reticence was a form of soft secrecy, designed to avoid soft bigotry. Revealing Mormon teachings would no longer have led to lynch mobs or federal arrest, but it certainly would have fueled the kind of bias that keeps politicians out of office."
Yet the face of Mormonism many Americans first encounter is one that Feldman only briefly mentions: "The church’s most inviting public symbols — pairs of clean-cut missionaries in well-pressed white shirts — evoke the wholesome success of an all-American denomination with an idealistic commitment to clean living." How can a missionary be secretive about his faith? In particular, attempting to convert people in a Christianity-dominated America requires missionaries to do exactly what Feldman declares Mormons haven't done, i.e. develop "a series of easily expressed and easily swallowed statements summarizing the content of their theology in ways that might arguably be accepted by mainline Protestants. To put it bluntly, the combination of secret mysteries and resistance in the face of oppression has made it increasingly difficult for Mormons to talk openly and successfully with outsiders about their religious beliefs."
I think the first Mormon I ever met was when I was taking a summer course at Trinity University in San Antonio. Being a college student, he simultaneously professed both skepticism toward and pride in his religious tradition. The only thing he told me about it that I remember is that God has a wife, but that we do not know Her name because God does not want us to take it in vain as we do His. I have no idea whether this actually is accurate Mormon theology, but I found the notion quite charming (Hindu gods don't always get along so well with their spouses). The next Mormons I met were two different pairs of missionaries while I was living in Northern Virginia before law school. They were all very nice and in both instances I would have been happy to talk theology with them had I not been on my way elsewhere.
Admittedly, a Hindu agnostic poses a different conversion project for a Mormon missionary than does the average American, who is a Protestant, but had it been my roommate who had come to the door, that would have been precisely the set of beliefs they would have faced. She was baptized and raised in the Methodist church, and was a believer in the vague way that twenty-somethings often are when they'd like to sleep late on Sundays but also intend to raise their children in some kind of organized religious tradition.
Thus the idea of Mormons as incapable of talking about their religion with Protestants just seems obviously wrong. Certainly a Mormon missionary and a Protestant evangelical might be at odds as each seeks to convert the other, but this isn't due to an inability to communicate the tenets of each one's faith. The mission mandates Mormons to be ready to discuss their faith with people who don't understand it. Indeed, this requirement ensures that they will be much more capable of doing so than I am at trying to explain a polytheistic religion that has no founder, to anyone coming out of the Abrahamic Western religions.