The Wisdom behind the Creation of Angels that record Deeds
Question:
Verily, Allah, the Most High has created for us Honorable Scribes who write down everything we say and hear. What is the wisdom behind their creation, bearing in mind that Allah, the Most Glorified, Most High knows (everything) and neither that which we hide nor that which we do openly is hidden from Him?
Answer:
First of all, in matters such as these, we might know the wisdom behind them or we might not; in fact, we do not know the wisdom behind many things, as Allah says:
"And they ask you (O Muhammad concerning the Ruh (the spirit). Say: "The knowledge of the spirit is with my Lord, and of knowledge you (mankind) have been given only a little.
These are created things. Were the questioner to ask me, for example: What is the wisdom behind the creation of the camel in this form, or the horse in that form, or the donkey in that form, or mankind in this form, and such like questions, and if we were to ask: What is the wisdom behind Allah's making the Zuhr prayer four Rak'ahs, 'Asr prayer four Rak'ahs and Isha' prayer four Rak'ahs and such like questions, we could not know the wisdom behind it. Indeed a questioner might ask: Why were they not made eight or six? Thus, we see that the wisdom behind many matters related to created things and even many of the religious legislative matters is hidden from us. Having accepted this, we may say that in seeking the wisdom behind every creature or every legislated matter, if Allah allows us to reach it, we should consider this to be an extra favor, knowledge and goodness. If we do not find it, we are not lacking anything.
Then we return to the question, what is the wisdom behind the appointment of the Honorable Scribes, who know what we do? The wisdom in it is that it shows that Allah, the Most Glorified, Most High has ordered all things and has prescribed everything to perfection, even to the Honorable Scribes who record all that the sons of Adam do, even though He, the Most Glorified, Most High knows what they will do even before they do it. All of this is because of His perfect care and attention to mankind and His perfect rule of this creation - and Allah knows best.
Source:
Ibn 'Uthaimin
Fatawa Islamiyah, Vol. 1 Pages 193-194-195