Portland, Ore., is No. 1 on the list of metropolitan areas with the most religiously unaffiliated residents (42%), according to the nonpartisan and nonprofit Public Religion Research Institute’s American Values Atlas, a survey of 50,000 people. Seattle and San Francisco were tied at second place (with 33%) on the list, and Denver (32%) and Phoenix (26%) were third and fourth.

On the other end of the spectrum, Nashville was the metropolitan area with the fewest people without any religious affiliation (15%), followed by Charlotte, N.C. (17%), and Atlanta, Dallas, Orlando and Pittsburgh (all with 18%). Some caveats: While many people who don’t believe in God may not attend religious services, there are (of course) faith traditions such as Unitarian Universalism that welcome and include humanists and atheists; many people ...