Ancient Mediterranean societies spent their everyday lives participating in the rites of various religious cults, which can be seen in the example of the roman colony of Salona. On the basis of material and literal evidence I investigate the effect of religion and cult on moral conduct of an individual person in antiquity. In order to describe the phenomena of religious cults in Salona, we need to differentiate two kinds of facts that we use in description of religion and cult in antiquity; facts about state of the affairs and facts about beliefs and values. While investigating the facts about state of the affairs, we arrive to description of the religious cults in Salona. On the other hand, while investigating the facts regarding beliefs and values, we arrive to the system of religious knowledge in antiquity. On the basis of metaethical research, we are justified to claim that beliefs and values of a religious cult could affect person's morality. That defines our method. So, in order to claim that religious cults in Salona existed, we need to perform a historiographic description. We investigate religious cults of; Jupiter, emperor cult, cult Cybele and Attis, cult of Silvanus and Liber, kult of Isis and Sarapis, Mithraism and Christianity. Next, in order to justify claim that religious cults could guide human lives, one needs to investigate how did the authors in antiquity define a relation between human and supernatural entities (and others), with both rules and values that one must follow. Lastly, on the basis of evidence in Salona I investigate the instructions by which religious cults in Salona could affect on the planning of the every-day conduct of their followers, which is based on the historiographical descriptions and history of ancient Mediterranean thought.