Spiritual health is a complex issue in terms of differences in the concept of spirituality, worldview and value systems, which is defined according to the specific insights of each group. On the other hand, belief in the best system implies theology, cosmology, anthropology and resurrection. Owing to this account, believing in the best system as a rational doctrine in the heavenly religions can provide successful strategies for promoting spiritual health. This article has been written with the aim of assessing the reflection of the belief in the best system in promoting spiritual health and epistemic excellence. Understanding the order of the world, comprehending the privileged position of man over other beings, and believing in the originality and eternity of the soul, will help us to understand the essential purpose of creation, that is, the perfection of the human spirit. By relying on the rational and innate arguments, man has realized that he cannot achieve the ultimate goal of creation by merely relying rationally on his understanding. Rather, achieving the ultimate perfection necessitates the attainment of spiritual health through the use of revelatory doctrines, epitomizing the divine prophets and the intellect as the ultimate devices for the legal and anatomical perfection of the human being. Therefore, it is pretty clear that a serious belief in the best system promotes spiritual well-being. Spiritual health also leads to epistemic excellence, that is, the meaning of life, spiritual vitality, the satisfaction of divine ordinances, the repulsion of the anxiety of death, the proper interaction with the society, nature, and ultimately, becomes the eternal happiness.