The Dutch intellectual Allard Pierson (1831–1896) is often considered to be an example of secularism. In 1865, he resigned as a minister from the Dutch Reformed Church in order to promote true humanity in society at large. This article explores how Pierson’s true humanity can be considered as an ultimate concern (Tillich) or a religion without religion (Caputo) by reading him through the lens of John D. Caputo’s thinking. Both Caputo and Tillich developed a non-institutional and undogmatic understanding of religion, in which religion is related to a universal human love, passion, or ultimate concern that is not necessarily linked to a religious institution or doctrine. After an elaboration of Caputo’s religion without religion, the article discusses Pierson’s thinking in the context of nineteenth-century theological modernism and debates on the modernist’s right to stay in the church. Then, Pierson’s reasons for his resignation and his true humanity are examined. It becomes clear that Pierson did not choose secularism over religion, but rather surpassed the religious-secular divide by a focus on our common human nature. Being human was more important than being Christian, which exemplifies the late-nineteenth-century move from a theistic Christianity towards a humanistic religiosity or humanism.