I can tell this question is meant for Christianity but I can only answer from the point of view of Lavenderism.
If Hechun (The king of heaven) was not the most powerful deity in existence, then he would have had his position usurped. This would be very bad because Hechun is benevolent towards humanity and governs the entire sky realm. If he was not the most powerful being, then it would be complete chaos in the spirit world and even in this physical world. The entire existence of everything would also not be engendered by Hechun if he was not the most powerful deity and therefore would not leave as strong of an impression on our reality as the most powerful deity. However most of us in the world of MEST (The physical world) probably would not know much different because Hechun is too distant to interact with in most cases, and any deity at that level would also be too distant from us to accurately gauge. The Celestial Bureacray would also be redundant if Hechun was not the most powerful deity, because then a more powerful could just ignore the will of the celestial bureaucracy.