Purpose of Honourable Scribes
Question

What is the reason for the existence of the honourable scribes even though Allah knows all things?
Praise be to Allah.We say concerning such matters: we may or may not understand the wisdom behind it, because we do not know the wisdom behind many things, as Allah says (interpretation of the meaning):
“And they ask you (O Muhammad) concerning the rooh (the spirit). Say: ‘The rooh (the spirit) is one of the things, the knowledge of which is only with my Lord. And of knowledge, you (mankind) have been given only a little.’” [17:85]. 
With regard to these creatures, if someone were to ask us: what is the reason behind Allah making the camel in this manner, and making the horse in this manner, and making the donkey in this manner, and making the human in this manner and so on; if he were to ask us about the reason or wisdom behind these things, we would not know. If we were to be asked: what is the reason why Allah has made Zuhr (midday) prayer four rak’ahs (units), and ‘Asr (late afternoon) prayer four, and Maghrib (sunset) three, and ‘Isha (night) four, and so on? We would not be able to know the wisdom behind that. 
Thus we know that with regard to many matters, both in the universe and in terms of sharee’ah (religious law), the wisdom behind them is hidden from us. As that is the case, we say: if we manage to understand the wisdom behind some things in creation or in sharee’ah, if Allah blesses us by enabling us to understand it, this is additional virtue, goodness and knowledge. If we do not understand it, this is not going to harm us in any way. 
Now let us go back to the question, which is what is the reason why Allah has appointed honourable scribes to record what we do? 
The wisdom behind this is to show that Allah has organised and measured all things in the most perfect manner, to such an extent that He has appointed honourable scribes to record the actions and words of the sons of Adam; they are enjoined to watch over them and write down all that they do, even though He knows what they are going to do before they do it. But this is a manifestation of the perfection of Allah's care for man and His complete protection, and it shows that this universe is organised in the best possible manner, and Allah is All Knowing, Most Wise.
And Allah knows best. End quote.