Habermas takes the enlightenment and secular religion as historically mutually antagonistic or exclusive. At the same time, Habermas claims that enlightenment and religion, knowledge and belief have common ethical content. How could the conflict occur between the two, if they have common content? In addition to this, how could they, which are historically mutually exclusive, be reconciled by “reflective leap” in modern society? For Hegel, belief and Knowledge have the same genealogical source, insofar as they are “flight from the actual world.” They have the same content insofar as they take the opposition of the actual world as it’s truth. But they are different only formally; belief expresses the truth in representative form, knowledge in conceptional. The formal differences between them allow them to criticize mutually and trigger dialectic of enlightenment and secularization of religion. Knowledge and faith, enlightenment and religion are only the two sides of the same coin, which can be taken as the process of self-understanding of the one and same spirit. We can get the possible foundation of “reflective leap”, Habermas highlights, from Hegel’s theory of the relationship between enlightenment and secularization.