A sect is a small religious group that has branched off of a larger established religion. Sects have many beliefs and practices in common with the religion that they have broken off from, but are differentiated by a number of doctrinal differences. In contrast, a denomination is a large, well-established religious group. The word sect comes from the latin secta, meaning an organized religious body or organization, from Latin, meaning a course of action or way of life.
Sociologists use the word sect to refer to a religious group with a high degree of tension with the surrounding society, but whose beliefs are (within the context of that society) largely traditional. Membership is by proof to sect authorities of some claim to personal merit. Such as knowledge of doctrine, affirmation of a conversion experience or recommendation of members in good standing; exclusiveness is emphasized and expulsion exercised against those who contravene doctrinal, moral or organization as precepts. Personal perfection is the expected standard of aspiration, in whatever the terms this is judged; it accepts, at least as an ideal, the priest hood of all believers.
There is a high level of lay participation, there is opportunity for the member spontaneously to express his commitment; the sect is hostile or indifferent to the secular order and to the state. Sects are concerned with purity of doctrine and with the depth of genuineness of religions feeling. As a result, demands are made upon the member to be an active participant, even a leader or missionary, as a warrant of his faith. The emphasis on purity of belief tends to create intolerance toward other groups and moves the sect toward critical assessment of the secular world in accordance with the ideals of the gospel. A cult, by contrast, also has a high degree of tension with the surrounding society, but its beliefs are (within the context of that society) new and innovative. Sects, in the sociological sense, are generally traditionalist and conservative, seeking to return a religion to its (perceived) religious purity. In European languages (other than English) the word 'sect' is used to refer to a dangerous religious sect, similar to how English-speakers popularly use the word 'cult'.