The paper analyses the limits to applicability of the “religious modernism” concept. Although the concept is deeply embedded in scientific vocabulary and included in most dictionaries of philosophy and religious studies, there are a number of theoretical and methodological problems, related to its usage. It regards, in particular, the academic taxonomy of phenomena developing on periphery of a religious system and incorporate elements of both religious modernism and religious fundamentalism. Identification of such phenomena through the prism of dichotomy “modernism/fundamentalism” less and less corresponds both to the character and depth of religious changes, and to the state-of-the art in humanities and social sciences.

The history of emergence and evolution of religious modernism shows that “religious modernism” is a complex, multilevel and multisided concept. On the one hand, “religious modernism” is a concept introduced in the Modernity era it is a religious expression of tendencies and connotations of this civilizational model. On the other hand, phenomenology, structural and functional peculiarities of religious modernism can serve as an important methodological prerequisite for identification of religious processes and phenomena resulting from the interaction between religion as a dynamic spiritual and social subsystem and society as a developing social system. In a post-secular context, when specific religious ideologies more often incorporate elements of fundamentalism and modernism, such integral approach helps to resolve objective complexity of the concept “religious modernism”, turning it into a suitable heuristic device to analyze complex forms of religion and religiosity.