Practical theology is one of the new epistemological concepts that has emerged in the Western world in the present era with the approach of practicalizing of theology, and thinkers such as Osmer have written works on this subject and have theories in this field. Despite its Western origin, this knowledge has opened its place in Islamic studies and has attracted the attention of Muslim thinkers, and its application in the field of approximation of Islamic religions can be one of its functions. In this article, with regard to the four pillars proposed in Osmer's theory, the application of Islamic theology at the functional levels of descriptive, experimental, interpretive, normative, and practical has been considered, especially with an emphasis on its practical functions in the field of approximation of Islamic religions. The findings of this research, which was conducted based on the collection of library information and in a descriptive-analytical manner, show that among the four functions of practical theology, the interpretive function and its normative function in approximation, i.e., changeability, along with the practical function, have the greatest impact on promoting a culture of approximation. In this regard, the role and function of scholars in realizing this, first among themselves and then in the Islamic society, is of particular importance, although this does not mean that the functions of governments and people are negated, and their role is also very prominent.