Delve into the Book of Mormon, some scholars say, and you'll find the Sermon on the Mount, rules, rituals and traditions that directly mirror the Holy Bible, which also is a sacred text of Mormonism.
What rankles conservative evangelicals who've called that religion anti-Christian and White House hopeful Mitt Romney, a Mormon, unfit for the presidency are Mormon amendments to a Bible that conservatives hold sacrosanct, even though, some scholars add, Christianity itself has morphed over the ages.
"The critics are concerned with the fact that the Church of Jesus Christ of Latter-day Saints, which is their formal name, has a third testament," said the Rev. Dr. Dale Irvin, New York Theological Seminary president, co-author of "History of the World Christian Movement" and an evangelical Baptist preacher.
He diverges with conservative views that 187-year-old Mormonism is a cult, as once described by the likes of controversial Rev. Dr. Robert Jeffress of Dallas, and that it's antithetical to Christianity. Many evangelicals describe Mormonism as non-Christian and cultish, according to a new Pew survey on Mormonism, Romney and the Republican primary.
Pew found that one-third of Republicans believe Mormons are not Christians. More than half (53 percent) of white evangelicals say Mormons are not Christians, the survey found.
"That third book scares them," Irvin added of the skeptics, "even though it's written in King James English and reiterates much of what's in the Gospels. To be really blunt, many of them haven't read it. To phrase it more seriously, it threatens the authority of Scripture, with a capital S, which evangelicals will say was written and closed with the apostolic era."
That era was around 70 or 80 A.D., scholars estimate. Since then, however, Mormons are the only avowed Christians to be ostracized for placing their own imprimatur on Christianity. For nixing infant baptism, the Church of England dismissed Baptists as heretics in the 16th Century, Irvin said, beginning a shortlist of inter-Christian conflict.
"There was a time when Seventh Day Adventists were considered to be un-Christian," he said. "New England Puritans hung Quakers by the neck over their differences. … The general theory, though, is that so-called fringe religions move back into the mainstream of history over time."
Mormonism has made its own efforts in that vein. Although a breakaway group still practices polygamy, the church outlawed that practice in the 1890s as Utah -- embattled Mormons, fleeing murder and other assaults on the East Coast, had resettled there -- sought to join the Union. And the church's whites-only membership rule got dropped in the 1970s. It added "Another Testament of Jesus Christ" as the Book of Mormon's subtitle in the 1980s.
Nevertheless, lingering challenges to Mormonism rest, for examples, on its followers' belief that founder Joseph Smith saw angels and discovered a third testament that Jesus had originally delivered to Native Americans, one of the 10 lost Hebrew tribes; that the dead can be baptized and, by so doing, get into heaven; that Jesus was, indeed, a great prophet but not as inextricably linked to God as depicted by mainstream Christianity's divine Trinity of the Father, Son and Holy Ghost.
"Mormons … have made strong movement to emphasize their genuine Christian credentials," said Patrick Mason, associate director of Claremont Graduate University's 3-year-old Mormon Studies Program in Claremont, Calif.
The Mormonism debate is, he said, "a fair discussion to have theologically and within religious circles. Absolutely. Especially when it's done with nuance and care and distinction. There is a nice, behind-the-scenes dialogue going on right now between Mormon leaders and [President] Richard Mouw at Fuller Theological Seminary. And no one would question his [evangelical] Christian orthodoxy … It's less clear to me why the debate matters for Romney's campaign."
The Rev. Dr. Harold Dean Trulear, a Howard University School of Divinity professor of the sociology of religion, said, "The whole country certainly isn't worried about this."
He started tracking Mormonism in 1975, when his senior thesis at Morehouse College in Atlanta spotlighted the church's ban on black members. "During the last 50 years, the landscape has changed," Trulear added. "There's far less animosity toward Mormons in the general population, but you've got these small, vocal segments on the margins."
What might quell some of the debate about Romney's suitability for office, the Rev. Edward Beck of ABC's "God Squad" said, is his own discussion of Mormonism.
"If we're going to make faith an issue of this campaign," Beck, a Passionist priest, said, "the candidates have to be willing to talk about it in an open way, especially if their faith will influence their governance."
Short of that, New York Theological Seminary's Irvin said, a more precise characterization of Mormonism is in order. "A cult means something which is secret, private," he said, citing the dismissal last month by Jeffress, a backer of GOP presidential contender Gov. Rick Perry. "So, using the language of cult is misleading and very uninformed."