A census of religious bodies in the United States taken once every ten years that reported a large growth in the Mormon population did so in part because the sect has changed the standard for which it identifies members.
The Association of Statisticians of American Religious Bodies' report had the population of the Church of Jesus Christ of Latter-day Saints at 4.2 million in 2000 and 6.1 million in 2010, noting a 45.5 percent increase. However, this dramatic increase is aided by the LDS Church opting to classify as members all who have been baptized in their sect, not just those who are currently belonging to a congregation.
Lyman Kirkland, who serves in the Public Affairs department of the LDS Church, told The Christian Post about the methodology used to count members.
"Total Church membership numbers are derived from those individuals who have been baptized or born into The Church of Jesus Christ of Latter-day Saints," said Kirkland. "They left out numbers of members who, although baptized, were not currently associated with a specific congregation. This year we included total membership numbers to more accurately reflect all of those found on church records."
Kirkland explained that under the previous methodology of only including baptized members associated with a specific congregation, the Mormon population estimates "were understated."
Regarding those who may have left the LDS Church or those belonging to Mormon sects not affiliated with the LDS, like the controversial FLDS Church headed by Warren Jeffs, Kirkland told CP that neither groups are counted.
"If a person has requested that their name be removed from church records, they are not included in membership counts," said Kirkland, who expects the current methodology for counting the Mormon population to remain in use.
At times charting membership numbers of various religious and ideological groups can be a challenge, especially as many question whether degree of participation should be factored into determining how strong certain groups and congregations are.
For the National Council of Churches' Annual "Yearbook of American and Canadian Churches," the Southern Baptist Convention has had issues in reporting its membership numbers. In 2002 and 2003, the SBC admitted to reporting errors with its membership numbers, which inflated their ranks by about 110,000. Even factoring out the error, SBC still came out as the second largest denomination in the NCC's Yearbook, with over 16 million members. The Roman Catholic Church, with 67.8 million members, was number one.
In a similar manner, even factoring out the additions garnered from including Mormons who have been baptized yet do not belong to a specific congregation, the LDS Church remains one of the fastest growing religious groups in the United States and one of the few sects not presently experiencing a decline in membership. Many Christians do not consider Mormonism as "historic biblical Christianity."