Various sociological classifications of religious movements have been proposed by scholars. In the sociology of religion, the most widely used classification is the church-sect typology. The typology is differently construed by different sociologists, and various distinctive features have been proposed to characterise churches and sects. On most accounts, the following features are deemed relevant:

The church-sect typology has been enriched with subtypes. The theory of the church-sect continuum states that churches, ecclesia, denominations and sects form a continuum with decreasing influence on society.^{[citation needed]} Sects are break-away groups from more mainstream religions and tend to be in tension with society. Cults and new religious movements fall outside this continuum and in contrast to aforementioned groups often have a novel teaching. They have been classified on their attitude towards society and the level of involvement of their adherents.

The church-sect typology has its origins in the work of Max Weber and Ernst Troeltsch, and from about the 1930s to the late 1960s it inspired numerous studies and theoretical models especially in American sociology.

Weber characterised the church as a compulsory, bureaucratic, inclusive organisation whose membership is obtained primarily at birth by ascription, and the sect as a voluntary, democratic, exclusive organisation whose members are recruited through individual admission after establishment of qualification. Ernest Troeltsch accepted Weber's definition but added the notion of a varying degree of accommodation with social morality: the church is intrinsically conservative, inclined to seek for an alliance with the upper classes and aiming at dominating all elements within society, while the sect is in tension with current societal values, rejects any compromise with the secular order and tends to be composed of underprivileged people.

Subsequent sociological and theological studies elaborated on Weber's and Troeltsch's typologies incorporating them into a theory of the church-sect "continuum" or "movement". H. Richard Niebuhr viewed religious groups as ranging between the poles of the sect and the church: sects are protest groups that break away from the church in search of more authentic religious experiences. Sects are inherently unstable and as they grow they tend to become church-like; once they have become established institutions, marked by compromise and accommodation, they are in turn exposed to new schismatic challenges. The sect is a result of "the religious revolts of the poor," and the driving force of the cyclical movement between sect and church is not so much doctrinal controversy as social stratification and conflict taking place along class, race, ethnicity and sectional lines.

Other scholars enriched the typology with subtypes. Howard Becker introduced a continuum of types ranging from the cult to the sect, the denomination and the ecclesia, and John Milton Yinger delineated a sixfold typology: the universal church (e.g., the Roman Catholic Church), the ecclesia, by which he meant established national churches (e.g., the Church of England, the Russian Orthodox Church), the denomination (e.g., Baptists, Presbyterians), the established sect (e.g., Seventh-Day Adventists, Quakers), the sect (e.g., many Pentecostals, the Worldwide Church of God) and the cult (e.g., The Family, Scientology). Benton Johnson simplified the definition of sect and church and based it on a single variable: the degree of acceptance of the social environment. A church is a religious group that accepts the social environment in which it exists, a sect is a religious group that rejects it.

The church-sect typology and the notion of a church-sect continuum or movement from the sect to the church came under strong attack in the sociology of religion of the 1960s onwards. The theory suffered from lack of agreement on the distinguishing features, from proliferation of new types and from questionable empirical evidence on its core assumptions. Many contributions to the debate were perceived as being pure classificatory in nature and devoid of significant theoretical content. Eventually there was general agreement among scholars to abandon use of the typology altogether, although the waning of the debate on the church-sect typology did not affect the persisting interest for Weber's contributions on the topic and more broadly for his sociology of religion. Moreover, notwithstanding the criticisms, the distinction between sect and church has become part of the standard theoretical repertoire of sociologists.

As Weber's ideas on church and sect have developed in the course of time, what follows is a sketch of key definitions and themes.