Studying the human’s need for legislative management (al-tadbir al-tashri’i), revelation or religion is an external studying of religion, and scholars have discussed this area in different ways, to which in this research we have generally referred to. However, the preferred way and what is presented here is based on logical steps that tries to accurately clarify the limits of the topic in order to distinguish it from other similar and related topics, tracing the roots of human’s need for religion. In accordance to this, we started by identifying the basic needs of humans, showing that the establishing the human’s needs lies in understanding the philosophy of his existence and the purpose behind his creation. We showed that knowing this fact lies in human’s knowing of himself, his powers and capacities. Furthermore, in order for irreligious people to reconcile between their view that there is no need for religion and their necessary need for a moral system to keep themselves safe from the harms of immorality, they claim that the human intellect is sufficient in defining morals and moral standards.  Even though we have acknowledged the possibility of generally perceiving the rational goodness and badness of actions, we have argued that the intellect is still in need of religion to be guided to a complete and coherent moral system, and, in fact, to know the higher levels of morality. We have argued that not seeking and not adhering to religion is one of clearest examples on immorality.