This article is meant to inquire the methodology, approach and value of Tang Jun-yi's study on the religiousness of Confucianism, observe his analyses about the factors in the spiritual structure of the natives of the central plains and the process whereby the beliefs in primitive divinities were "naturally transformed" into "philosophical convictions." Tang expressed and argued for this very process from the perspective of "syncretizing religions through humanism" while this article would trace to the formation background and foundation of this concept, pointing out its reasonableness and methodological importance with special regards to Tang's theoretical foundation in Chinese philosophy, the limits of his forms of expression, the principles of transformation between religion and philosophy and the reflection on how one's imagination cannot abide in an surreal world.