Data source: Gina A. Zurlo, ed., World Christian Database (Leiden/Boston: Brill, 2025).
| Glossary item | Definition |
|---|---|
| Independents | Churches or individual Christians separated from, uninterested in and independent of historic denominationalist Christianity. |
| indigenous Christianity | In a particular region, that type of Christianity which, in contrast to imported or foreign types, is evolved or produced by populations indigenous to that region. |
| infant baptism | In Catholic, Orthodox, Anglican, Lutheran, Methodist, Reformed and other traditions, the administration of baptism to children under 5 years old. |
| infants | Children or babies under five years old. |
| interdenominational | Occurring between or among or common to several or many different denominations; accountable to several denominations, or partially or completely controlled by them. |
| Islamic schismatics | Followers of Islam, in other than its 2 main branches of Sunni or Shia. Islamic schismatics include Kharijite and other orthodox groups; reform movements (Sanusi, Mahdiya), also heterodox groups (Ahmadiya, Druzes, Sabbateans). |
| Ismailis | Followers of Ismailiya (also known as Seveners). Second largest part of Shia Islam and itself divided into Nizari Ismailis (Khojas) and Mustali Ismailis (Bohras). |
| isolated radio/TV churches | Indigenous house churches or groups composed of isolated radio/TV believers, brought into being solely through Christian broadcasting and/or Bible correspondence courses by mail; isolated from existing Christians. |
| itinerant | Adjective describing an evangelist, missionary or other church worker whose ministry involves being continually on the move from one city or people or country to the next. |
| Jains | Followers of the two traditions, Svetambara and Digambara; originating in India as a reform movement from Hinduism in the 5th or 6th century BCE. |
| Jehovah’s Witnesses | An Independent tradition founded in 1872; also called Russellites. |
| Jews | Followers of the various schools of Judaism: in the United States: Orthodox, Conservative and Reform; in Israel: Haredi, Orthodox, Traditional, Observant and secular; ethnically, Ashkenazi (Eastern Europe), Mizrachi (Middle Eastern), Sephardic (Iberian Peninsula). |
| jurisdiction | (1) Any territory within which a bishop or other church leader exercises his authority, such as an archdiocese, diocese, vicariate, prefecture, etc. (2) In some churches, a jurisdiction (symbol J) is a specific type of territory similar to a diocese. |
| Lamaists | Lamaism. Tantrayana, or the Tantrism school of Buddhism (qv). |
| Latin rite | Forms of Christian worship and liturgy utilising or based on Latin; that part of the Catholic Church that employs Latin liturgies. |
| Latin-rite Catholic | That part of the Roman Catholic Church that employs Latin liturgies (forms of Christian worship and liturgy utilising or based on Latin). |
| Latter Rain | A type of Perfectionist-Pentecostals claiming to inaugurate the Latter or Springtime Rain cited by Old Testament prophets as immediate precursor to the second coming of Christ. |
| Latter-day Saints | Followers of the Church of Jesus Christ of Latter-day Saints, an Independent Christian movement based in Salt Lake City, Utah, or of its break-off groups; also called Mormons. |
| Lutherans | Followers of Martin Luther and the original 16th-century German Protestant protesting tradition. |
| Mahayanists | Mahayana. The Greater Vehicle school of Buddhists (qv), or Northern Buddhism (China, Japan, et alia). |
| mainline Christianity | Relating to the historic Protestant churches of Northern and Western Europe (such as Methodist, Presbyterian, Lutheran). |
| Mandaeans | Gnostics (Mandaiia), followers of 2nd-century CE Jewish-Christian fertility religion (Christians of St John, Followers of John the Baptist, Dippers, Sabaeans, Nasoreans), regarding John the Baptist as the Messiah. |
| Maronites | Catholics of Antiochian rite. |
| martyr | Christian who loses his or her life, prematurely, in a situation of witness, as a result of human hostility. |
| megachurch | Very large local congregation or church; in a demographic sense, refers to a congregation or church with a membership over 2,000. |
Data on 18 categories of religion, including non-religious, by country, province, and people.
Data on all religions, Christian activities, and trends.
Membership data, year begun, and rates of change.
Population and religion data on all major cities & provinces.
Detailed information covering religion, culture, and geography.
A repository of historical data, including a chronology of Christianity from the 1st to 21st centuries.