What is the purpose of the reflections of punishment of God?

A lesson of truth from the Risale-i Nur Collection: It is required that a Sultan has mercy and favor on his right and punishment and taming on his left. Reward is the pre-requisite of mercy. And taming calls for punishment. The place of reward and punishment is the Hereafter. (Mesneve-i Nuriye)

As it is not suitable for the greatness of the sultan not to award the ones who obey him, so it is also not suitable not to punish the ones who rebel; both of them are an expression of weakness and inability. God Almighty is free of these kinds of weaknesses.

Wanting his punishment not to take place comes to two meanings:

First, not punishing the rebels, the aggressors, and the cruel. This is contrary to the greatness, wisdom, and justice of God. As this is not possible, there is one option left: Second, the condition of man being innately incapable of riot, and being always obedient. This, however, is the definition of the angel, not human.