Americans are less religious than they were eight years ago, with members of the millennial generation less likely to pray or go to church regularly, according to a new, sweeping study of religious beliefs conducted by the Pew Research Center.

The survey found that the United States remains far more religious than other Western nations, but with wide variations in religious belief and practice. Such cities as Seattle, which has long been known as "unchurched," and San Francisco show far less religious practice than the country as a whole.

The Pew survey, which involved 35,000 people, found that 70.6 percent of Americans still identify themselves as Christian, although 20.8 percent are now listed as "nones," answering that they are atheists, agnostics or just "nothing in particular" with respect to religious beliefs. Belief in God is still strong at 89 percent, but down from 92 percent in 2007.

In the Seattle area, however, just 52 percent of residents identify as Christian, while the figure in greater San Francisco is 48 percent. The "nones" make up 37 percent of Seattle's population, with 10 percent atheist, 6 percent agnostic, and 22 percent "nothing in particular." Thirty-five percent of Bay Area residents list no religious affiliation.

Compare these figures to greater Houston and the Dallas-Fort Worth metropolitan area. Houston voted Tuesday to roll back its LGBT rights ordinance, 37 years after Seattle voted to sustain its ordinance prohibiting discrimination against gays and lesbians.

Seventy-three percent of Houstonians and 70 percent of those living in Dallas-Fort Worth identify themselves as Christians. The "nones" total just 20 percent in Houston and 18 percent in Dallas-Fort Worth.

Just 49 percent of greater Seattle residents believe in the existence of heaven, with 40 percent as disbelievers. Hell does worse. Thirty-four percent of those surveyed in greater Seattle believe in a fiery inferno presided over by Satan, while 58 percent do not. Eight percent don't know, but will presumably find out when they die.

By contrast, by a 76-17 percent margin, greater Houston believes in heaven, with hell getting a 65-28 percent thumbs-up. Seven percent don't know. Dallas-Fort Worth believes in heaven by a 75-18 percent margin, and affirms hell by 63-30 percent.

The millennials are changing Pew's findings about religion.

Nationally, about half of those born between 1990 and 1996 believe absolutely in the existence of God, compared to 71 percent from the "lost generation" born between 1928 and 1945. Just 39 percent of millennials pray daily or worship regularly, compared to 67 percent for their elders.

The Pew survey caught another trend -- the decline in religious observance and belief in New England, and particularly such former bastions of Roman Catholicism as Rhode Island and Massachusetts. The archdiocese of Boston suffered deep, self-inflicted wounds by covering up priest pedophilia until the scandal broke open on pages of the Boston Globe in 2002.

Just 57 percent of greater Boston residents now identify as Christian, and only 29 percent as Catholics. The "nones" total 33 percent. Providence remains more religious, with 72 percent identification as Christian and 46 percent as Roman Catholic. Still, the "nones" at 23 percent were greater than the national average.

Seattle has always been a city with low church attendance. Local religious leaders have cited its Scandinavian heritage, as well as a tendency of people to "leave behind" traditions -- including religious traditions -- when residents begin a new life in the Northwest.

The absence of people automatically in the pews has, however, spurred both an ecumenical and social activist tradition among Puget Sound area churches.

Episcopalians and Lutherans were joining in worship long before the tradition was formalized by their parent denominations. KOMO-TV was running a regular discussion program with a priest, minister and rabbi just as the Catholic Church was opening itself to other religious traditions under Pope John XXIII. Catholic priests were at the altar in St. Mark's Cathedral for its annual Thanksgiving eucharist.

The Seattle religious community took a lead role in 1960s civil rights activism, and in the 1970s battle to end banks' redlining of minority neighborhoods.

In recent times, the Seattle-area faith community launched the gun-safety movement that led to statewide Initiative 594, requiring criminal background checks for those purchasing firearms at gun shows or online.

Pew found that Americans are sorting themselves politically in accordance with their religious beliefs.

Evangelical Christians, about 25 percent of the population, make up 38 percent of the country's Republicans (and a vast majority of caucus-goers in Iowa, the first test of presidential candidates).

The "nones," at 20.8 percent of the population, break two-to-one for the Democrats. Roman Catholics comprise about 21 percent of membership in each of the political parties.