Interesting piece of information. It comes from the LDS website so one may want to cross reference it if possible. Christian Churches/ Churches of Christ are in the top 25 in this list.
The two fastest-growing churches in the United States and Canada are Jehovah’s Witnesses and The Church of Jesus Christ of Latter-day Saints, according to the National Council of Churches’ 2008 Yearbook of American & Canadian Churches.
Although Jehovah’s Witnesses currently rank 25th in size with over 1.06 million members, they reported a 2.25 percent increase in membership in a year. The Church of Jesus Christ of Latter-day Saints grew 1.56 percent and is listed as the fourth largest “church.”
The following are the largest 25 churches in the US and Canada (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
