This article analyzes the dynamics of the content of the freedom of religion aiming to reflect the transformation of the right to freedom of religion in historical perspective and forming generalized models of such content, as well as prognosing the prospects for further dynamics of these changes. The relevance of the study is justified by several factors. Firstly, the issue of exercising the right to freedom of religion is urgent in the context of the growing number of followers of various religions, as well as the use of religious narratives for political purposes. Secondly, contemporary factors shaping post-secular society (diversification of attitudes towards religion and types of religiosity) contribute to the erosion of the classical definition of the subject of freedom of religion. Thirdly, forecasting the further development of freedom of religion requires an analysis of its formation and historical transformations, which remains insufficiently studied in domestic doctrine. The article argues that the content (subject) of freedom of religion (especially within the European tradition of understanding it) has undergone significant changes, influencing the concepts and scope of state-confessional interaction, as well as the principles of defining relevant norms. Therefore, it is necessary, having examined individual epochs of the formation of freedom of religion, to identify its general meaning and development trends. Such research is conducted based on historical-legal sources and doctrinal knowledge. It is argued that the historical development of freedom of religion demonstrates its dynamic evolution and the acquisition of an increasingly broader scope. The ancient vision of freedom of religion is characterized by the assertion of adherence to one of the alternative cults (territorially defined) as a legal duty. However, the common background (principle) of all cults does not allow for choice and thus leads to the implicit leveling of the significance of freedom of religion. In medieval law, freedom of religion is explicitly leveled; adherence to a single cult is affirmed as a legal duty (reception of obligation with denial of alternative compared to antiquity). Actual freedom of religion emerges in modern times as the ability of individuals to choose and change beliefs freely and to freely practice their religion. This process is accompanied by the formation of a secular state. Partial freedom of religion, based on limited state-sanctioned choice, later transforms into full freedom with unrestricted free choice. Such a concept prevails in international law and national legislation currently. Further development of freedom of religion is possible in the context of challenges of post-secular society, including diversification of attitudes towards religion and types of religiosity, as well as the spread of a worldview based on non-religious faith. This concept has now seen the most development in the practice of interpretation and application of the European Convention on Human Rights, as set out in the decisions of the European Court of Human Rights. This practice requires detailed study in further research.