This article examines Islamic thought in general and theology in particular in terms of the relationship between physics and metaphysics, based on Aristotle's Physics VIII, and reevaluates Averroes' (d. 595/1198) criticism of Avicenna (d. 428/1037) and Ash`ari theology regarding the matter of proof for God's existence. Averroes claims that the Ash`ari theology lacks metaphysics, so the huduth evidence (the proof of contingency) contains structural problems. Drawing from Averroes' analysis, the cosmological arguments revolving around theologians' proof of God's existence from the universe's contingency have developed into a profoundly intricate framework, generating polemics to the extent that even scholars in the field struggle to grasp its intricacies. Expanding on this point, theologians' efforts to establish God's existence often exacerbate rather than alleviate complexities surrounding the relationship between contingency and eternity (physics and metaphysics). On the other hand, Averroes maintains his silence against Avicenna and Avicenians, who seem to have solved the main problems regarding the eternal-temporal dichotomy through metaphysics, and criticizes them for rendering Aristotelian physics inactive in the proof of Necessary Being. Conversely, Averroes remains unconvinced by the theologians' cosmological/ physics-based arguments through the proof of contingency. However, when viewed from the perspective of Averroes, the theologians were neither able to solve the problem of the relationship between eternal and temporal with metaphysical propositions nor were they able to correctly apply physical principles in their cosmological arguments. The assertion that theologians could not implement physics accurately also carries the insinuation that they failed to formulate a coherent metaphysical framework. Is Averroes right, and do Avicenna's and the theologians' proofs for God's existence contain structural problems regarding the physics-metaphysics relationship? Is physics still necessary in terms of proof of God's existence? Or is physics sufficient to prove God's existence? Is it possible to have a proof for God's existence without metaphysics? What kind of problems does neglecting physics or metaphysics cause? The study will examine these questions from various perspectives.