In the seventeenth-century Dutch Republic, non-professional theologians articulated well-informed biblical interpretation, producing a lay theology that was unwelcome to representatives of the churches. Historians have long considered this lay theology as a manifestation of Early Enlightenment. It did not, however, necessarily result from the activities of rationalist philosophers usually associated with the Dutch Early Enlightenment, such as Benedictus de Spinoza (1632–1677). Equally important were the clergy’s efforts to educate laity in reading the Bible and contemplating divinity autonomously. This paper reconstructs the Dutch “culture of catechesis,” a collective effort to involve laity in reflection on religion and the Bible, dating back to at least the 1640s. Based on catechetical materials and their authors, this paper argues that the “culture of catechesis” had its roots in the Public Church itself, and that it contributed to lay theology, as much so as the outspoken programs of eccentric philosophers.