Abbreviation GIS is an equivalent for both science and technology and comes with its own approaches and theories for processing and evaluating various data. Also therefore GIS technologies are currently penetrating various fields of science. This contribution is focused on specific issues connected with application in studies of historical religions within GEHIR project (A Generative Historiography of the Ancient Mediterranean), which is focused mainly on the ancient Mediterranean. Selected issues as nature and properties of historical spatial data, environmental modelling in religious studies etc., will be demonstrated on example of case study dealing with the cult of Isis. Results show potential of GIS for purposes of research studies in the field of the Religious studies.