Nondenominational (or non-denominational) churches are those which typically distance themselves from the confessionalism and/or creedalism of other Christian communities by calling themselves non-denominational. Often founded by individual pastors, they have little affiliation with historic denominations, although they almost always adhere to Evangelicalism.
There is no identifiable standard among such congregations. Nondenominational church congregations may establish a functional denomination by means of mutual recognition of or accountability to other congregations and leaders with commonly held doctrine, policy and worship without formalizing external direction or oversight in such matters. Some nondenominational churches explicitly reject the idea of a formalized denominational structure as a matter of principle, holding that each congregation is better off being autonomous. This is a main feature of the congregational polity.
Many of the nondenominational churches trace their origins back to the United States. Their history is often deeply entangled with that of American Protestantism, even though nondenominationals emphasize their Christian identity above all others. A 2012 Gallup survey reported that 10 percent of U.S. adults identify as non-specific Christian.
According to James Walker:
The visible churches, in the idea of the Scottish theologians, is catholic. You have not an indefinite number of Parochial, or Congregational, or National churches, constituting, as it were, so many ecclesiastical individualities, but one great spiritual republic, of which these various organizations form a part. The visible church is not a genus, so to speak, with so many species under it. It is thus you may think of the State, but the visible church is a totum integrale, it is an empire. The churches of the various nationalities constitute the provinces of this empire; and though they are so far independent of each other, yet they are so one, that membership in one is membership in all, and separation from one is separation from all... This conception of the church, of which, in at least some aspects, we have practically so much lost sight, had a firm hold of the Scottish theologians of the seventeenth century.
Denominationalism was accelerated in the aftermath of the Westminster Assembly convened by the English Parliament to formulate a form of religion for the national churches of England and Scotland. In the debate between the two main parties present at the Assembly, the Presbyterians and the Independents, the Presbyterians were in favour of a form of church government that maintained the visible organizational unity of the Catholic Church while Independents, weary of the ecclesiastical tyranny they experienced under the Episcopal system, wished to organize the churches in a congregational way envisioning no legitimate authority of the church above the local congregation meeting at one time in a single place. These two parties were not reconciled and following the Assembly the Independents formed their own independent church. Thus, instead of a united expression of the Catholic Church in England, there were now two churches.
Protestant denominations spread and multiplied, especially in the United States, as denominational confessional statements began to be used more to exclude than to include Christians with different doctrinal convictions. Each denomination maintains to differing degrees some form of organizational and visible unity with its member churches, albeit radically decentralized compared with the Catholic Church.
Ordination and education standards in non-denominational church are very diverse. The Christian Leaders Alliance, for instance, has ordained over 400 leaders from 2014-2016 where the ordination candidate receives their training through Christian Leaders Institute, but must have three local endorsements. A local Christian Leader must sign the local non-denominational ordination. 
Today, non-denominational churches, like the Independents at the Westminster Assembly, refuse to recognize any ecclesiastical authority above the local congregation and deny the visible unity of the Church (though not the unity of the invisible Church) despite the fact that the original denominations were formed by substantially the same ideology.
Boston University religion scholar Stephen Prothero argues that nondenominationalism hides the fundamental theological and spiritual issues that drove the division of Christianity into denominations in the first place behind a veneer of "Christian unity". He argues that nondenominationalism encourages a descent of Christianity—and indeed, all religions—into comfortable "general moralism" rather than being a focus for facing the complexities of churchgoers' culture and spirituality. Prothero further argues that it also encourages ignorance of the Scriptures, which in turn reduces overall religious literacy, increasing the potential for inter-religious misunderstandings and conflict.
Jonathan A. Mitchican, a traditionalist Anglican priest, has also argued that the term non-denominational is essentially misleading: "If an American church calls itself 'non-denominational,' nine times out of ten what that means is Baptist. Altar calls and appeals to personal conversion replace the sacraments as the means of grace. Baptism is a symbol of one's personal conversion, nothing more, and it is only appropriate for adults."
- Community Church movement
- Non-church movement
- Non-denominational Muslims
- Non-denominational Judaism
- Sunday Christian
- Confessionalism is a term employed by historians to refer to "the creation of fixed identities and systems of beliefs for separate churches which had previously been more fluid in their self-understanding, and which had not begun by seeking separate identities for themselves—they had wanted to be truly Catholic and reformed." (MacCulloch, The Reformation: A History, p. xxiv.)
- Allan Anderson, An Introduction to Pentecostalism: Global Charismatic Christianity, Cambridge University Press, UK, 2013, p. 157
- "Classification of Protestant Denominations" (PDF). Pew Forum on Religion & Public Life / U.S. Religious Landscape Survey. Retrieved 27 September 2009.
- Nondenominational Congregations Research at Hartford Institute for Religion Research website. Hirr.hartsem.edu. Retrieved on 2010-11-03.
- "Religion". Gallup. 2012.
- World Council of Churches: Evangelical churches: "Evangelical churches have grown exponentially in the second half of the 20th century and continue to show great vitality, especially in the global South. This resurgence may in part be explained by the phenomenal growth of Pentecostalism and the emergence of the charismatic movement, which are closely associated with evangelicalism. However, there can be no doubt that the evangelical tradition "per se" has become one of the major components of world Christianity. Evangelicals also constitute sizable minorities in the traditional Protestant and Anglican churches. In regions like Africa and Latin America, the boundaries between "evangelical" and "mainline" are rapidly changing and giving way to new ecclesial realities."
- Religion in Global Civil Society by Santa Barbara Mark Juergensmeyer Professor of Sociology and Director of the Global and International Studies Program University of California
- Note that in this quotation the word "catholic" is used in the sense of "universal." Dr. James Walker in The Theology of Theologians of Scotland. (Edinburgh: Rpt. Knox Press, 1982) Lecture iv. pp.95–6.
- "Get Ordained - Christian Leaders Church". Retrieved 2016-09-15.
- "Ordination Information - Christian Leaders Church". Retrieved 2016-09-15.
- Prothero, Stephen (2007). Religious Literacy: What Every American Needs to Know - and Doesn't. New York: HarperOne. ISBN 0-06-084670-4.
- "Ask an Anglican: An Evangelical, a Baptist, and a Charismatic Walk Into a Bar…".