To its harshest critics, Unitarian Universalism is a religion — like "Seinfeld" — about nothing.
There are no required rituals. There is no church doctrine. Members don't even have to believe in God to belong.
But for centuries, most members have shared principles: They've been committed to progressive movements, from abolition to gay rights.
Now a group of churchgoers, including some political conservatives, is accusing the denomination of replacing spirituality with social activism. They're forming a rival organization to attract like-minded Unitarian Universalists.
The split has manifested itself as a trademark lawsuit over who has the right to the name American Unitarian Association, but the real divide is over the definition of religion.
"To a non-Unitarian Universalist, the idea that there needs to be a major effort to restore God to religion is oxymoronic," said David Burton, a 41-year-old lobbyist and co-founder of the maverick group. "But in many Unitarian Universalist congregations, and at the Unitarian Universalist Association, it is sometimes controversial to talk about God and the divine."
The Rev. John Buehrens, president of the Unitarian Universalist Association, the Boston umbrella group for the denomination, argues Burton and his supporters are driven by politics.
"They claim a theological motive, but when you have a paid conservative lobbyist at the core of it, you wonder," Buehrens said.
The debate moves to Cleveland where the Unitarian Universalists, with 220,000 members, began their annual meeting on Thursday.
Burton chose the name American Unitarian Association when he incorporated his group in his home state of Virginia. The Unitarian Universalist Association sued, arguing the name, which they never registered as a trademark, became their property in 1961 when Unitarians and Universalists merged.
"They are appropriating to themselves the Unitarian Universalist Association's history and goodwill and tradition," said Edward Leibensperger, the attorney representing the UUA.
The case also raises questions about who has rights to millions of dollars the Unitarian Universalists have been collecting from trusts established in the name of the American Unitarian Association. Burton said he would be willing to sign away any legal right to those funds.
The Unitarians, with roots in a movement that rejected Puritan orthodoxy in New England, are famously resistant to dogma. They have considered removing any reference to "God" from their principles.
Members say Unitarian Universalism is the only religion that allows them to change theology without changing churches.
"Almost all of us went through a long period of agnosticism and atheism," said the Rev. Carl Scovel, who led the Unitarian Universalists' Kings Chapel in Boston for nearly 40 years.
That questioning has led the denomination to take liberal positions on hot-button religious and political issues over the years.
The Universalists ordained their first female minister in 1863. Churchgoers were among the more active supporters of the civil rights movement.
Yet some Unitarians fear their denomination has become nothing more than a political debate club.
Buehrens questioned why Burton did not follow the lead of others in the denomination to form an affiliate group, such as the Unitarian Universalist Christians or Unitarian Universalist Humanists, under the UUA umbrella.
Burton felt that approach would have been ineffective.