Nondenominational Christianity (or non-denominational Christianity) consists of churches which typically distance themselves from the confessionalism or creedalism of other Christian communities by not formally aligning with a specific Christian denomination. Many non-denominational churches have a congregationalist polity, which is self-governing without a higher church authority.
Nondenominational Christianity first arose in the 18th century through the Stone-Campbell Restoration Movement, with followers organizing themselves simply as "Christians" and "Disciples of Christ".[note 1]
Often congregating in loose associations such as the Churches of Christ, or in other cases, founded by individual pastors, they have little affiliation with historic denominations, but many typically adhere to a form of evangelical Christianity. Most Nondenominational Christians in the United States fall under Protestantism.
Nondenominational Christianity first arose in the 18th century through the Stone-Campbell Restoration Movement, with followers organizing themselves simply as "Christians" and "Disciples of Christ". Congregations in this tradition of nondenominational Christianity often refer to themselves as Churches of Christ.
Nondenominational congregations experienced significant and continuous growth in the 21st century, particularly in the United States. If combined into a single group, nondenominational churches collectively represented the third-largest Christian grouping in the United States in 2010, after the Roman Catholic Church and Southern Baptist Convention.
Nondenominational churches are not affiliated with specifically denominational stream of evangelical movements, either by choice from their foundation or because they separated from their denomination of origin at some point in their history. Like denominational congregations, nondenominational congregations vary in size, worship, and other characteristics. Although independent, many nondenominational congregations choose to affiliate with a broader network of congregations, such as IFCA International (formerly the Independent Fundamental Churches of America).
Some non-denominational churches identify solely with Christianity. 
Boston University religion scholar Stephen Prothero argues that nondenominationalism hides the fundamental theological and spiritual issues that initially drove the division of Christianity into denominations 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, lowering the overall religious literacy while increasing the potential for inter-religious misunderstandings and conflict.
Baptist ecumenical theologian Steven R. Harmon argues that "there's really no such thing" as a nondenominational church, because "as soon as a supposedly non-denominational church has made decisions about what happens in worship, whom and how they will baptize, how and with what understanding they will celebrate holy communion, what they will teach, who their ministers will be and how they will be ordered, or how they relate to those churches, these decisions have placed the church within the stream of a specific type of denominational tradition." Harmon argues that the cause of Christian unity is best served through denominational traditions, since each "has historical connections to the church's catholicity ... and we make progress toward unity when the denominations share their distinctive patterns of catholicity with one another."
Presbyterian dogmatic theologian Amy Plantinga Pauw writes that Protestant nondenominational congregations "often seem to lack any acknowledgement of their debts and ties to larger church traditions" and argues that "for now, these non-denominational churches are living off the theological capital of more established Christian communities, including those of denominational Protestantism." Pauw considers denominationalism to be a "unifying and conserving force in Christianity, nurturing and carrying forward distinctive theological traditions" (such as Wesleyanism being supported by Methodist denominations).
Richard T. Hughes, professor of religion at Pepperdine University, argues that the Churches of Christ built a corporate identity around "restoration" of the primitive church and the corresponding belief that their congregations represented a nondenominational Christianity.
Not A Denomination: For this reason, we are not interested in man-made creeds, but simply in the New Testament pattern. We do not conceive of ourselves as being a denomination–nor as Catholic, Protestant, or Jewish—but simply as members of the church which Jesus established and for which he died. And that, incidentally, is why we wear his name. The term “church of Christ” is not used as a denominational designation, but rather as a descriptive term indicating that the church belongs to Christ.
Barton Stone was fully prepared to ally himself with Alexander Campbell in an effort to promote nondenominational Christianity, though it is evident that the two men came to this emphasis by very different routes.
Later proponents of Campbell's views would refer to themselves as the “Restoration Movement” because of the Campbellian insistence on restoring Christianity to its New Testament form. ... Added to this mix were the concepts of American egalitarianism, which gave rise to his advocacy of nondenominational individualism and local church autonomy, and Christian primitivism, which led to his promotion of such early church practices as believer's baptism by immersion and the weekly partaking of the Lord's Supper.