van Jaarsveld, after whom the Biermanskool Reformed Church was originally named Vanjaarsveld in honor of his pioneering work in South West Africa (SWA), helped as a custodian in services for the Reformed Churches in the north of the mandate territory.
He helped found Grootfontein in 1943, as he had the Outjo Reformed Church (1930), the second oldest congregation in northern Namibia.
On September 17, 1949, the young GKSA congregation petitioned the city government for their own church grounds.
The site was located on historic grounds where the Angola-Boers of the Dorsland Trek, under the leadership of their president Diederik Prinsloo, had founded the Republic of Upingtonia (in existence from 1885 to 1886).
The church branded the best of the cattle, the farmers grazed them for free, and proceeds from their sale went directly towards the building project.
One of the elders on the building committee, Jan Harm (Boet Jannie) du Plessis (born July 28, 1921, Mombolo, Angola, and died May 14, 1984, in Walvis Bay), had a father, Lourens Marthienus du Plessis, who was born June 19, 1886, in the short-lived Upingtonia, on the church's future grounds.