The First Commandment played an important role in the theology of Karl Barth. His personal obedience to this commandment contributed to his realization that one cannot be comfortable with the Liberal theology of the early twentieth century and accept the theological thinking that supported National Socialism. The First Commandment opened his eyes to see the idols, worldviews, ideologies and evil of his lifetime. The First Commandment is always in the background of his theology that concentrates on God's revelation in Jesus Christ. Only two of his lectures specifically concentrated on the First Commandment, only one of which was published. Barth, understood the First Commandment as an axiom of theology. It is self-evident; a cornerstone and critical guideline for any theology that is built upon the biblical message. The article argues that if this aspect of Barth's theology received attention in the Nederduitsch Hervormde Church, we would most probably have been saved from the conflicts concerning the ideology of apartheid and the "people's church".