The previous post on Common Grace may be found here.
In the 25th chapter, Kuyper asks what sort of consciousness did Adam possess? What could it possibly mean to Adam to be told of death & life? How could Adam know what was presented him when he met Eve (or Eve, Adam)?
Kuyper argues that Adam and Eve were possessed of a moral clarity which would escape us at this point: The law of God was not merely an appendage to their knowledge, it was the framework of their understanding.
Moreover, the content of their knowledge would be bracketed with their conscious realization that I was not but now I am.
Having moral capacity and an understanding of existing or not Adam had the capacity to understand the prohibition to not eat from that Tree. It was an arbitrary command, in the sense that it was not immediately apparent from the natural ordering of the world. To not strike Eve when she came to him would be part of the natural moral order: it is good to not hurt this fellow human being.
But what motivation would then exist to refrain from the Tree. It is not a question of natural law, but a question of positive command: why obey this positive command? Or, as Kuyper puts it, will you obey because it is good, or will you obey because God has so commanded it. The goal was that Adam would obey because of fealty to God.
He provides an analogy: If you give one a command and the other demands an explanation, (what is the purpose of this command, what will be the benefit to me and so on), eventually obedience will not be obedience to command but rather is a decision that I think this is a good idea.
The moral development of Adam was thus to be two-fold: first, there was the development of the delight in good and doing good. Second, this development and delight in good was to be because it was given by God.
The apparent insignificance of the command, this tree and not some other, had in it the point of the commandment: there could be no motivation for the command beyond God’s authority.
The purpose of the command was to test Adam to see if he would obey because he had been so commanded by God.