In this paper, the term "Priority theology" is introduced to describe the theological system of Abu al-Husayn al-Basri in discussing the problem of divine action or, more generally, the problem of "God and the world." He believed that in a causal relationship, the cause does not necessitate the effect but only makes the effect more likely to occur. According to him, since nature as a whole and as a collection of things and relationships is a creation of a Free God, the natural relationship, causality in nature, is only preponderant (أولی), not necessary; therefore, peripatetics and asharits' ideas of necessity and coincidence in causality are inaccurate. According to priority theology, God can act freely to create the world, choose states and objects for existence, and reset or change natural flows. Furthermore, priority theology emphasizes the role God, man, and nature play in reality. The explanation of miracles done by prophets, miracles of saints, answering prayers, termination of decisions, and appearance (بداء) in al-Basri's theology show that man and nature follow the order and authority established by God. However, God can intervene in the world for some reason, such as the revelation of his power and authority. By presenting a theological analysis of the philosophical approach, al-Basri's theology could create a new way of defending theological claims. Later, Ibn al-Malahim, Fakhr al-Din al-Razi, Sadid al-Din al-Hemmasi al-Razi, Khawaja Nasir al-Din al-Tusi, Allama Helli, and others welcomed his theological way and established the basis for their theological systems. Some of the effects and consequences of al-Basri's priority theology include presenting new definitions of necessity, further explanations of causality in the world, the solution of predestination and delegation through intermediate position, miracles, and the like, and finally, solving the problem of evil.