Jehovah's Witnesses and the Church of Jesus Christ of Latter-day Saints reported the largest membership increases in a year, according to an annual yearbook of churches.

The two groups are largely considered to be cults by evangelical Christians but they are currently the fastest-growing church bodies in the United States and Canada, the National Council of Churches' 2008 Yearbook of American & Canadian Churches showed.

Although Jehovah's Witnesses currently rank 25th in size with over 1.06 million members, they reported a 2.25 percent increase in membership since the publication of the 2007 Yearbook. The Church of Jesus Christ of Latter-day Saints – also known as Mormons – grew 1.56 percent and is the fourth largest church body.

Other bodies in the top 25 largest churches list that reported membership increases include The Catholic Church with a 0.87 percent increase; the Southern Baptist Convention with a 0.22 percent increase; the African Methodist Episcopal Zion Church with a 0.21 percent rise; and the Assemblies of God with a 0.19 percent growth.

The greatest losses in membership were reported by The Episcopal Church, which dropped 4.15 percent in members, and the Presbyterian Church (U.S.A.), which decreased by 2.36 percent. Both denominations are currently wracked by theological differences and the issue of homosexuality.

American Baptist Churches in the U.S.A. and the Evangelical Lutheran Church in America also experienced large losses in membership, dropping 1.82 percent and 1.58 percent, respectively.

"Some will wish to argue that the slowing growth rate is evidence of an increasing secularization of American postmodern society," said the Rev. Dr. Eileen W. Lindner, editor of the Yearbook. "While such an explanation will satisfy some, caution in drawing such a conclusion is warranted."

Lindner also observed that churches are feeling the impact of the lifestyles of Millenials – people in their 20s and 30s – who attend church but resist becoming members.

The United Methodist Church saw a 0.99 percent decrease but the mainline group remains the third largest church body with nearly 8 million members.

Only three of the top 10 largest churches are mainline Protestant churches; three of the top 25 are Pentecostal churches; and six of the top 15 are historic African American churches.

Largest 25 Churches (ranked by membership)

1. The Catholic Church – 67,515,016
2. Southern Baptist Convention – 16,306,246
3. The United Methodist Church – 7,995,456
4. The Church of Jesus Christ of Latter-day Saints – 5,779,316
5. The Church of God in Christ – 5,499,875
6. National Baptist Convention, U.S.A., Inc. – 5,000,000
7. Evangelical Lutheran Church in America – 4,774,203
8. National Baptist Convention of America, Inc. – 3,500,000
9. Presbyterian Church (U.S.A.) – 3,025,740
10. Assemblies of God – 2,836,174
11. African Methodist Episcopal Church – 2,500,000
12. National Missionary Baptist Convention of America – 2,500,000
13. Progressive National Baptist Convention, Inc. – 2,500,000
14. The Lutheran Church - Missouri Synod (LCMS) – 2,417,997
15. Episcopal Church – 2,154,572
16. Churches of Christ – 1,639,495
17. Greek Orthodox Archdiocese of America – 1,500,000
18. Pentecostal Assemblies of the World, Inc. – 1,500,000
19. The African Methodist Episcopal Zion Church – 1,443,405
20. American Baptist Churches in the U.S.A. – 1,371,278
21. United Church of Christ – 1,218,541
22. Baptist Bible Fellowship International – 1,200,000
23. Christian Churches and Churches of Christ – 1,071,616
24. The Orthodox Church in America – 1,064,000
25. Jehovah’s Witnesses – 1,069,530