Factbox: Mormonism and its relation to Christianity

(Reuters) - The question of whether United States Republican presidential hopeful Mitt Romney, a Mormon, is a real Christian emerged at a weekend meeting of social conservatives as a potential dividing line between him and evangelical Christian rival Rick Perry.

Following are facts about Romney's Church of Jesus Christ of Latter-day Saints (LDS), as the Mormon church is formally called, and the issue of whether it is truly Christian:

* The once-isolated church, based in Salt Lake City, Utah, is one of the fastest-growing and most affluent religions. More than half of its 14.1 million members live outside the United States, with a flourishing flock in Latin America.

* Mormonism was founded in 1830 in upstate New York by Joseph Smith, who said he received the word of God from an angel named Moroni, who guided him to tablets that told the story of the Book of Mormon about an ancient civilization of Israelites sent by God to America. A year later, he was persecuted and forced to flee to the Midwest, where he was killed. His followers then undertook a mass 1,100-mile (1,800-km) migration in 1846-47 to Utah.

* Mormons have three books of scripture other than the Bible. One is the Book of Mormon, which Mormons believe was translated from golden plates discovered by Smith. Adherents, who do not use alcohol, coffee and tobacco, believe that God speaks through living apostles and prophets such as the church's president, Thomas Monson. Mormons also believe that Jesus visited the Americas after his resurrection and that there is no eternal hell.

* The Mormon church originally allowed polygamy. Smith took at least two dozen wives, say historians. The custom was officially banned in 1890 as Utah sought statehood. A dissident Mormon sect, the 40,000-strong Fundamentalist Church of Jesus Christ of Latter Day Saints, upholds polygamy. Its leader, Warren Jeffs, is serving a life sentence for sexually assaulting two girls he wed as "spiritual brides" when they were 12 and 14.

* Today, more than 50,000 missionaries project a wholesome, family-oriented image that has helped swell global Mormon adherents by 36 percent from 1995 to 2005.

* The LDS Church says it is truly Christian, believes in Jesus Christ and corrected mistakes it says mainline Christianity made in its early centuries. But it has a different view of the Trinity from mainline Christians and additional teachings -- such as the prophesies of Joseph Smith, Jesus's visit to America, baptism of the dead or the existence of God the Father married to a Heavenly Mother -- that those churches reject as unbiblical or un-Christian.

* While most Christian churches do not require rebaptism if a believer switches from one denomination to another, Mormons do not recognize baptisms in other churches and require all converts from those churches to be rebaptised. The Roman Catholics and Methodists require converts from Mormonism to be rebaptised while other Christian churches cast serious doubt on the validity of Mormon baptism.

(Reporting By Tom Heneghan; Compiled by Jason Szep and Tom Heneghan; Editing by Andrew Heavens)