Abstract: What true context does Schleiermacher's On Religion assume has always been the research focus of the academic community. Different from the traditional view, this paper studies the key influence of Spalding who was the spirit leader of Neology on On Religion. When Schleiermacher came to Berlin in 1797, he formed the close bonds with Spalding and saw the latter as his spirit mentor. Comparing Spalding's Religion, a Human Affair (1797) with Schleiermacher's On Religion (1799), we find that they have lots of similarities in writing objects, style, and key concept. What is more important, they share two important themes. The first is their understanding of reality as a system of interdependence, and the second is the goal of community which is the inevitable result. Only in the context of Spalding can we get a true understanding of On Religion.