Karl Theodor Jaspers was a German-Swiss psychiatrist and philosopher who had a strong influence on modern theology, psychiatry, and philosophy. Influenced by Kant, Kierkegaard, and Nietzsche, Jaspers is sometimes portrayed as an existentialist, though he did not accept the label. He is perhaps best known for his concept of the Axial Age, which he introduced in his book The Origin and Goal of History. Rudolf Karl Bultmann was a German Lutheran theologian and professor of New Testament at the University of Marburg. He was one of the major figures of early-twentieth-century biblical studies and a prominent voice in liberal Christianity. Bultmann relied on demythologization, an approach interpreting the mythological elements in the New Testament existentially. Bultmann contended that only faith in the kerygma, or proclamation, of the New Testament was necessary for Christian faith, not any particular facts regarding the historical Jesus.

