Christina speaks from experience. In addition to being an atheist who came out to her family and friends nine years ago, she is also married to another woman.
Her message is knowingly patterned on the experience of the LGBT community, which has long encouraged lesbians, gays, bisexuals and transgender people to be public about their sexuality. Only by doing so, the thinking goes, can homosexuality be destigmatized and equality achieved.
And it's worked.
Gay marriage is now legal in 17 states. There are openly gay members of Congress and professional sports teams, and Hollywood has a firmament of gay and lesbian stars.
Just this week, at the White House Easter Prayer Breakfast, President Barack Obama asked Gene Robinson, an openly gay Episcopal bishop, to give a benediction.
So why shouldn't atheists take a page from the gay playbook? In the past decade or so, many atheist and humanist leaders have begun to openly acknowledge they can learn from those who fought for equality before them.
"I am learning not only from the gay-rights movement, but the civil-rights movement and the women's liberation movement," said David Silverman, president of American Atheists, who invited Christina to speak at the 2012 "Reason Rally," which drew upward of 10,000 nonbelievers to the Washington Mall. "Closeted LGBT and closeted atheists have the same problems. And the LGBT movement is going to win and so are we."
Studies show atheists need to improve their image. A 2006 study conducted by researchers at the University of Minnesota found atheists are the most mistrusted and disliked group of Americans and "a glaring exception to the rule of increasing tolerance over the last 30 years," in the words of the researchers.
Five years later, a study conducted by the University of Oregon and the University of British Columbia found that the distrust of atheists stems not from dislike, but from "moral distrust." In other words, a large segment of Americans believes atheists, because they do not have any religion, have no morals.
"There are a lot of myths ... about atheists," Christina said. "There is the belief that we don't have any morality, any meaning, any joy in our lives. There's an idea that we are just in rebellion against religion, that we don't want to follow rules. When there is stigma against you, it makes life harder for a hundred different reasons."
The first step in the solution is for nonbelievers to come out and show they have the same desires, concerns and problems as their religious neighbors, she said. From there, they can build communities and find support — the things many religious believers say they find in their houses of worship.
"Coming out helps normalize nonbelief," said Kurt Volkan, founder of Pitchstone Publishing, which published "Coming Out Atheist" and other books about nonbelief. "And normalizing atheism helps create space for nonbelievers in all parts of the country and allows them to interact with friends, families and co-workers in an open and honest way. The more people who encounter nonbelievers, the more accepted they will be."
Still, Christina wants atheists to come out only if they consider it "safe" to do so. For the book, she gathered more than 400 "coming-out stories" from nonbelievers around the world. All but one said their lives were better for having done it.
"That is one of the things that really struck me," she said. "When you are in the closet and there is stigma against you, you tend to internalize that stigma. But if you speak up and say that stigma is wrong, you don't have to take that negative opinion into you. Living in fear is difficult."