The Netherlands Reformed Churches (Dutch: Nederlands Gereformeerde Kerken, NGK) was a conservative Reformed Protestant Christian denomination in the Kingdom of the Netherlands.
The denomination was formed in 1967 following a schism within the Reformed Churches in the Netherlands (Liberated).
The latter denomination arose out of a conflict within the Reformed Churches in the Netherlands over the covenant and the power of the general synod.
Wary of the liberal tendencies within various Reformed denominations, they started to develop a number of cultural and political structures and institutes, whose membership was restricted to church members.
Van der Ziel was accused of errors in his teaching and was found guilty by the synod of the Reformed Churches (Liberated), which defrocked him.
However, local church councils responded by excommunicating members who had signed the petition.
Even though the widespread desire to be reunited to each other had been hampered by deep-running disagreements over both doctrine and practice, the two denominations officially merged into the Dutch Reformed Churches in 2023.
It also had a translating Reformed literature agency, this was the Spanish Work in Latin America.