Mozambique's religious geography was drawn by the Indian Ocean long before it was drawn by Europe. The gold and ivory trade tied its northern coast into the Swahili world, and Islam took root in ports such as Angoche and on the islands centuries before Vasco da Gama touched land in 1498; Sufi brotherhoods later carried the faith inland and gave northern Muslim communities their characteristic devotional life.
The Portuguese brought Catholic missions up the Zambezi, Jesuits and Dominicans among the prazo estates, and in the late colonial period the church operated much of the education system under a concordat with Lisbon, a closeness that cost it dearly when Frelimo took power in 1975. The new Marxist state nationalised mission schools and hospitals, discouraged worship, and watched congregations shrink into private life, before war and pragmatism softened the policy in the 1980s; John Paul II's visit in 1988 sealed the reconciliation.
Meanwhile Zionist and Apostolic churches, carried home by migrant labourers from South African mines, spread through the south with healing rites that spoke to older spirit beliefs. The 2017 census caught the result, a country of Catholic, Muslim, Zionist and Pentecostal quarters, none dominant, layered over ancestor obligations that most Mozambicans still honour.