It’s a bit like holding the Republican National Convention in Berkeley: This weekend, the American Atheists are gathering in Salt Lake City for their annual conclave. Attendees can hear a keynote speech by outspoken former Vikings punter Chris Kluwe, attend workshops with titles like “So you want to debate Christians?” and mingle during a karaoke night and a costume dinner.

The whole event is taking place at a downtown Hilton, just three blocks away from Temple Square, spiritual and administrative capital of the Church of Jesus Christ of Latter-day Saints. The convention has its official opening on Good Friday. It concludes on Easter.

Mormons believe that, shortly after his resurrection, Jesus made a quick trip to the New World. They celebrate the season with passion plays and church services. The American Atheists, right next door, are passing their time drinking traditional convention cocktails: Madalyns (named after American Atheists founder Madalyn Murray O’Hair, who launched the atheist organization, America’s first, back in 1963) and Hitches (in honor of Christopher Hitchens, and featuring Johnny Walker Black Label).

Dave Muscato, the public relations director for the American Atheists, admitted to The Daily Beast that the timing is “kind of a poke in the eye to religion that makes us laugh a little bit.” He notes, though, that holding the convention on Easter weekend is also practical: “Atheists tend to have little else to do, and we can actually get quite a bargain at convention centers, because few other groups want to have a convention on Easter weekend.” As for the location, “We generally go for cities where there’s a good religious population, because those are the places where people tend to be the most oppressed by religion.” Muscato explains that the goal of the convention is to reach suppressed atheists in Salt Lake City, not to convert Mormons.

Still, the whole spectacle can’t help but seem like a provocation. (The church declined to comment for this article). Last fall, the AA clashed with some Salt Lake residents—the city is about 50 percent Mormon—over a billboard campaign that mimicked language used in LDS communities and advertisements. And, this month, in partnership with the Atheists of Utah, the AA sponsored a gathering in which 75 inactive Mormons publicly resigned from the church during the Mormons’ annual General Conference.

Really, though, the American Atheist convention in Salt Lake City is not a clash of opposites. It’s the convergence of unlikely cousins. The convention this week will bring together in Salt Lake City two distinctly American movements, with remarkably similar demographics, that are in the process of emerging into a public sphere that has long considered them suspicious outsiders.

For Mormons, that suspicion goes back to the 1800s, when, as a young movement, they were driven from town to town and subject to anti-Mormon riots (the Mormon founder, Joseph Smith, was killed by a mob in Illinois). That suspicion subsided a bit, helped by the church’s renunciation of polygamy in 1890, and cropped up again in the 1980s and 1990s, the result of scandals, a slow adoption of racial equality, and attacks from some right-wing evangelical Protestants. Mormons have been rehabilitating that image in recent years, through advertising campaigns and the so-called Mormon Moment in 2012.

Atheists, meanwhile, are among the least trusted groups in America. Just 54 percent of Americans, in a 2012 Gallup poll, said that they’d vote for an atheist presidential candidate. The American Atheists got started in the 1960s, in the face of stiff public opposition, but they’ve really been joined only in the last decade by other significant atheist organizations, all of whom are still trying to negotiate how, exactly, to help atheism become a more widely accepted identity.

The opposition that both groups faces is, in the annals of American prejudice, rather odd, and for two reasons.

The first is that, by any measure, it’s hard to imagine anything more homegrown and all-American than Mormonism and organized atheism. The Latter-day Saints, after all, have a church that mixes Protestantism with Masonic-tinged rituals, whose founding documents speak of American Christians and a New York-born prophet, and read like the bastard children of the Constitution and the King James Bible.

Meanwhile, organizations like the AA have helped transform atheism from a theological position to a movement, an identity, and a culture. Organizing atheists, some say, is like herding cats. That it’s been happening so much, especially in the past decade or so, seems like the undivine fulfillment of Alexis de Tocqueville’s observation that “Americans of all ages, all conditions, and all dispositions constantly form associations.”

And, in a second rarity, it’s strange to see two groups that have received such widespread mistrust despite occupying, in almost every other way, a position of social privilege.

Both groups are overwhelmingly white—82 percent of self-identified atheists and agnostics, and 88 percent of Mormons, according to recent Pew Research Center data. (The United States is 68 percent white). Both groups comprise about 2 percent of the American population, and both tend to be a bit more affluent than the American population as a whole, with just 28 percent of self-identified Mormons and atheists living in households that make less than $30,000 per year, compared to a full 36 percent of the general population.

According to Pew, close to two-thirds of those who identify as atheist or agnostic are men. While the founder of the American Atheists is a woman (who, like Joseph Smith, was murdered), both Mormons and organized atheists have a history of heavily male-skewed leadership—in the Mormon Church, it should be noted, as a matter of policy.

In short, both atheists and Mormons are American insiders and persistent outsiders, trying to assert a public identity and grow in prominence, even while they hold principles that baffle most Americans.

Tricky, right? The solution, naturally, is advertising. And that’s the one other thing that the Latter-day Saints and the American Atheists have in common, apart from most other (a)theological organization in America: absolutely top-notch PR.

For the Latter-day Saints, recently, that has meant a series of campaigns that, as Brigham Young University scholar J.B. Haws told me, are “less scripted, and a little more trying to individualize Mormonism” than previous outreach efforts. The campaigns focus a little less on family building, and a little more on personal identity. This includes the “I’m a Mormon” campaign, which shows ordinary Mormons looking ordinary, and the Mormon Identities project, which shows ordinary Mormons sounding ordinary.

All of which brings us back to the AA billboards, which, last fall, took the “I’m a Mormon” campaign and reimagined it as “I’m an atheist.” The campaign ended up showing ordinary atheists, young and old, looking—you know where this is going—friendly and very ordinary. Like so many other American Atheist campaigns, this one received significant media coverage—as I said, they’re good at PR—but Muscato insists that, while the billboards were “supposed to be cute” and “supposed to be funny,” they were not meant to anger Mormons.

I’m inclined to believe him. After all, the campaign doesn't need to provoke, because it seems to work just as well for atheists as it does for Mormons as a way to leverage the ordinariness of their otherness in the pursuit of visibility.

The American Atheists do seem aware that their organization has certain things in common with the LDS Church—even though, as Muscato notes, the AA does believe that the church is “a scam,” Joseph Smith “a con artist,” and Mormon beliefs “a myth.” Last Wednesday, the American Atheists hosted a public panel that brought together AA President David Silverman, the ex-Mormon writer Joanne Hanks, and two BYU professors, including Haws, an expert on public perceptions of Mormonism.

“The idea, basically, is that there are so many misunderstandings about what Mormons really believe,” says Muscato. “We wanted to give Mormons a chance to talk about what they really are like, and what they really teach. And the same is true of atheists. A lot of people in Utah are very unfamiliar with what atheists really believe and how we approach life.” Haws, whom I spoke with shortly before the panel discussion, said that he was “excited to consider some things from their perspective.”

Suffice it to say that, at least in a strategic sense, those perspectives might not be so different. The American Atheists don’t try to convert believers, but with a recent push for atheist evangelization, the Latter-Day Saints soon might not be the only group treading your streets in search of the lost. Both groups, more broadly, may represent the shared face of religion and irreligion in the 21st century: organizations that exist outside the declining Protestant mainstream, draw on a narrative of past persecution, speak the language of identity politics, and advertise as much as they possibly can. Is it working? Well, the Mormons just had their Moment. And as for the atheists? While churches might be in decline, their numbers are growing.