The Reformed religion in South Africa originated when Jan van Riebeeck, the first white man to settle in Southern Africa, made a covenant with God, that (among others) he would spread the Reformed faith in their new country. Boers see themselves as bound to this covenant.
The spiritual birth of the Boer people is generally considered to be their Great Trek, which took place during the first half of the 19th century. Apart from the desire to remain independent from foreign rule, another major reason for this migration, is the Anglicanization of the Dutch Reformed Church in the Cape. In the Covenant of The Battle of Blood River, still observed by Boers on the 16th of December every year, the Voortrekkers declared their people's complete dependence on God for their existence.
Two Boer Republics were founded in the 1850s and the Nederduitsch Reformed Church in Africa - NH Church was the national Church in the South African Republic (1852) and the Orange Free State (1854) was named after the Calvinist House of Orange in the Netherlands. Many Boers were members of the conservative Reformed Churches in South Africa, founded in 1859.
Because the Trekkers were partly isolated from Europe, they remained free from many of the liberal tendencies like rationalism and individualism, which influenced European Calvinism during the 19th century.
While many Boers were members of the Nederduits Gereformeerde Kerk in the past, very few have remained as the church has gradually grown more liberal. The same can be said of the Nederduitsch Reformed Church in Africa - NH Church, although in this denomination, as well as in the Reformed Churches in South Africa, Boers remain a significant minority. Boers now compromise the overwhelming majority of the members of the Afrikaans Protestant Church and the smaller Afrikaans Reformation Church.
The BCVO ('Movement for Christian-National Education') is a federation of 47 Calvinist private schools, primarily located in the Free State and the Transvaal, committed to educating Boer children from grade 0 through to 12.