By Jennifer Dobner

SALT LAKE CITY (Reuters) - A group of about 150 Mormons quit their church in a mass resignation ceremony in Salt Lake City on Saturday in a rare display of defiance ending decades of disagreement for some over issues ranging from polygamy to gay marriage.

Participants from Utah, Arizona, Idaho and elsewhere gathered in a public park to sign a "Declaration of Independence from Mormonism."

"This feels awesome," said Alison Lucas, from West Jordan, Utah, who took part in the rally amid soaring temperatures. "I don't know if I would have had the courage except in a group."

The Utah-based Church of Jesus Christ of Latter-day Saints is known for its culture of obedience, and the mass ceremony was a seldom-seen act of collective revolt.

After gathering in the park, participants hiked a half-mile up nearby Ensign Peak, scaled in 1847 by church President Brigham Young to survey the spot where his Latter-day Saints would build a city.

At the top, those gathered gave three loud shouts of "Freedom," cheered, clapped and hugged.

"It's been a hard journey and this is a symbolic end," said event organizer Zilpha Larsen, of Lehi, Utah. "I just hope that it boosts people up and helps them feel more comfortable in their decision."

The church bills itself as the one "true" Christian faith, and its theology promises families eternal relationships among those who remain faithful, sealing those gifts through special religious rites.

Among the reasons cited by those resigning are the church's political activism against gay marriage and doctrinal teachings that conflict with scientific findings or are perceived as racist or sexist.

Others cite inconsistencies in the Mormons' explanation of its own history, including the practice of polygamy. The church renounced plural marriage over a century ago as Utah was seeking statehood.

Asked about the resignations, a church spokesman said the church loves and respects each member.

"People make their own decisions about the direction they will follow in life," spokesman Michael Purdy said in an email. "While there are very few who take this action, it is sad to see someone choose to leave. We wish them well."

The most recent figures show the Mormon church claims 14.4 million members worldwide. The number of those resigning from the church are not publicly reported.

Among prominent Mormons is Mitt Romney, the presumptive Republican presidential nominee facing off against President Barack Obama in November. Should he win office, Romney would be the first Mormon elected to the White House.

'WE HAVE TO BE CAREFUL'

Some leaving the church Saturday did so with trepidation, as Mormon culture often stigmatizes those who fall away, leaving some without social or business connections. Continued...