This study examines the central challenge of reconciling divine justice-particularly within the framework of the Best Possible Order (al-Nidham al-Aḥsan)-with the reality of human suffering. It begins by establishing a clear conceptual distinction between evil, understood in philosophical terms as the privation of perfection, and pain, conceived as the existential and experiential manifestation of that privation. The study ultimately seeks to demonstrate how suffering, despite its apparent negativity, can be harmonized with absolute divine wisdom by virtue of its developmental and transformative role in human existence. Methodologically, the research adopts an interdisciplinary approach that integrates the conceptual precision of contemporary analytic philosophy with the metaphysical insights of the Islamic philosophical tradition. To move beyond purely abstract theorization, the analysis is further informed by empirical findings from the behavioral and biological sciences. In particular, it draws upon the "Universe 25" experiment and the psychological framework of Post-Traumatic Growth (PTG) to develop a comprehensive and multidimensional account of suffering and its significance. The study advances several major conclusions. First, it establishes a fundamental ontological distinction between evil and pain: whereas evil possesses only a privative and accidental mode of existence, pain constitutes a positive existential reality that fulfills indispensable protective, cautionary, and survival-oriented functions. Second, it argues that existential mutual hindrance (tazaḥum) is a structural and unavoidable law of the material world, such that its complete elimination would entail the dissolution of the material order itself. Third, the emergence of moral evil is interpreted as an inevitable existential consequence of granting human beings real free will. Finally, through an epistemological analysis of the Qur'anic narrative of al-Khiḍr (peace be upon him), the study underscores the inherent limitations of human cognition in apprehending the totality of divine purposes and wisdom. The narrative thereby serves to justify the eschatological horizon as an epistemological necessity-one indispensable for resolving the problem of absolute justice and for understanding the manner in which the human soul attains growth, elevation, and perfection through the crucible of suffering.