Systemic outlook to understanding religion considers the whole world and religion as a network of systems and subsystems. The objective of each system is the most important component; The objective of each system determines the sources, logics and understanding methods and each field’s subjects and problems. In the system of religion, the most fundamental basis is monotheism, then the other bases are justice, moral values and the reliable epistemological sources, common law, the requirements of time and place, …. Religion’s outlook to man, society, history and international system are the bases and main criteria of all scientific fields and the whole different measures. There is complete harmony among the bases, principles and different parts of all different fields of religious knowledge on one hand and beliefs, values and behaviours on the other hand. The whole system of religion is noetic (aqlāni) and rationalis (oqalāei), and simultaneously it is in agreement with narration (naql), and innate (feţri) attitudes and awareness and also intuitions. In the case taking advantage of true and deep logic of thinking, we can see the perfect agreement among the system of religion, the system of world, man’s natural disposition, man’s expediency, including the individual and collective happiness.