In a November Pew Research Center survey, about half of the white evangelical Christians polled said Mormonism is not a Christian religion.
Jan Shipps, a noted scholar of Mormon history and professor emeritus of history and religious studies at Indiana University-Purdue University Indianapolis, said that evangelicals have been taught to treat Mormons as "heretics."
The tension between evangelicals and Mormons owes partly to the fact that, for years, "they were tilling the same fields," as they sought converts in American suburbia, she said.
When evangelicals realized that Mormons were winning converts, the "development of the evangelical argument that Mormons aren't Christian was emphasized very strongly," said Shipps, who is a United Methodist.
But there are stark theological differences, too, between traditional Christians and members of The Church of Jesus Christ of Latter-day Saints.
And evangelicals are not the only Christians who believe these theological differences place Mormons outside the realm of Christianity.
While Mormons embrace the Bible, they also believe in an additional book: the Book of Mormon.
Mormons believe that in1823, in western New York, Joseph Smith - the founder of the LDS Church - was visited by an angel, named Moroni, who told him of an ancient record. In 1827, Smith received the record, which was written on gold plates, and translated it. The Latter-day Saints believe this was the Book of Mormon, another testament of Jesus Christ.
As the LDS website explains, the Book of Mormon "recounts Christ's visit to the American continent soon after His resurrection. He invited the people to feel the wound marks in his hands, feet and side. He blessed and healed them" and performed miracles. And he called 12 disciples to restore his church.
Mormons understand themselves to be "the restoration of the primitive church, the church that existed in the days of the first Christians," Shipps said.
In the view of the United Methodist Church, this means that the LDS church, "by self-definition, does not fit within the bounds of the historic, apostolic tradition of Christian faith."
Mormons believe in an open scripture, and continuing revelation.
For Christian fundamentalists, who regard the Bible to be the literal word of God, there can be no other scripture beyond the Old and New Testaments.
Moreover, traditional Christians regard belief in the Trinity - Father, Son and Holy Spirit, as one - to be essential.
But Mormons see God and Jesus as physical beings distinct from one another, and believe that Jesus is the literal son of God. As the LDS website explains, God "has a body that looks like ours, but God's body is immortal, perfected, and has a glory that words can't describe."
"That's just not Christian," the Rev. Serene Jones, president of Union Theological Seminary, a liberal Protestant seminary in New York City, told The New York Times. "God and Jesus are not separate physical beings. That would be anathema. At the end of the day, all the other stuff doesn't matter except the divinity of Jesus."
Kenneth H. Miller, professor of Christian theology at Evangelical Theological Seminary in Myerstown, said the nature of Jesus is indeed the crux of the matter.
Traditional Christians believe that Jesus is the only one who was ever "fully God and fully man," he said.
In Miller's view, Mormons do not draw a clear enough distinction between the nature of Jesus and the nature of human beings.
And the Book of Mormon's recounting of Jesus' "purported appearance" in America, after his resurrection, also is problematic to traditional Christians, Miller said.
Traditional Christians believe that, given all of Jesus' teachings in the New Testament, "no further revelations would seem to be necessary for our salvation," Miller said.
Mormons believe that in the afterlife, those who have followed the Gospel, and have married in the temple, will have their physical selves restored. Couples will live as families in the celestial kingdom.
When a Mormon couple marries in a Mormon temple, they are sealed for time and eternity.
A temple is used for special religious ordinances, or ceremonies, including marriage. Temples are distinct from LDS churches, where Mormons attend Sabbath Day services, said David Kenley, bishop of the Elizabethtown ward, or congregation.
Lancaster County has four LDS wards. The Elizabethtown and Lititz wards worship at a newly constructed LDS church, which opened last year, in East Hempfield Township. The Ephrata and Lancaster wards meet at an LDS facility on East King Street in Lancaster. Kenley estimates that 1,600 LDS members belong to the four wards.
Contact Sunday News staff writer Suzanne Cassidy at firstname.lastname@example.org.