Religious Beliefs. Virtually all Batak have converted to Islam or Protestant Christianity over the last 170 years, although in some areas beliefs that spirits can infest people and make them ill remain strong. An older Batak pantheon of creator deities and mythical clan founders has largely been eclipsed by the world religions. Batak converts often speak of an older "Age of Darkness" before their forefathers found out about "true religion." The southern Batak areas of Angkola-Sipirok and Mandailing converted to Islam starting in the 1820s; these are markedly pious, learned areas today, with many hajji and Quranic schools. Toba is a similarly serious, well-schooled Christian area, with many ministers and religious teachers. Karo is a region of much more recent conversions: pagan areas remain, and some villagers and townspeople converted to world religions in 1965, to avoid being labeled Communist sympathizers in the national unrest attending the establishment of the Suharto regime.
Each area has a varying syncretic blend of Islamic or Christian figures with indigenous spirits; the latter are a very minor part of the system of thought in long-converted areas. With increasing literacy, the old creator deities and the figures of myth have generally been demoted to the status of folklore figures.
Religious Practitioners. All areas have the standard religious personnel of world Islam and Christianity, as well as curer-diviners who contact supernaturals through trances and perform exorcisms.
Ceremonies. Most areas have split off adat, or custom, from agama, or true religion (that is, Islam or Christianity). This strategem allows Batak to remain pious monotheists and to maintain an elaborate round of adat ceremonies, with ritual Speeches, dances, processions, and gift exchange. Adat ceremonies focus on lineage ancestors, births in the lineage, and marriage alliance (with long, contentious weddings).
Arts. Nineteenth-century European missionaries discouraged carving and ritual dirges and dances, fearing these were blasphemous. This eliminated much of Toba's magnificent traditional sculpture and masked dances. House architecture in the old Great-House style has become too expensive to maintain today; few "Cosmic Houses" remain. Batak textile arts still thrive, as these cloths are still a vital part of marriage and mortuary exchange.
Medicine. Modern, scientific medicine is practiced by a thin network of government health workers, based in clinics, while curer-diviners practice alongside them, concentrating now on "spirit infestations" and some aspects of childbirth and poison control.
Death and Afterlife. Resilient beliefs in powerful lineage ancestors exist in some areas in tandem with the afterlife theories of Christianity and Islam. Adat's ceremonial speeches can be used to invoke the blessings of long-dead lineage ancestors. Masked dancers once served as mediums for ancestors to interact with living persons, but such performances have now been redefined as quaint customs.