The article examines the nature of the legal relations between the members of a religious group, a religious association, that operates without state registration and lacks the status of a legal entity. The law does not define formal criteria that would allow for the unequivocal determination of whether a religious group has been established. Between the members of a religious group, there are stable ties that arise from a voluntary expression of will and are directed toward the achievement of a common goal. Comparing how the nature of these legal relations is understood in foreign law with general conceptions regarding the nature of legal relations within an association of citizens suggests the hypothesis that contractual, private law relations exist between the members of a religious group. Based on this hypothesis, options are proposed for improving state regulation of the establishment and activities of religious groups.