Therefore...
Therefore, the vital significance of a solid, accurate, and fair law to guard the rights of the society and individuals is evident. Now the question is who should draw up this law? Who is the best law-maker? And what are his qualifications?
The first qualification is that the law-maker should be aware of the mental, physical, emotional and instinctive traits of those to whom the law would be applied and such perfect awareness is not possible for anyone except God, because He is the creator and only He is truly aware of the internal as well as the external dimensions of mankind and their mental and physical peculiarities.
Only God is cognizant of the various incidents happening in man’s life and the developments occurring in the society and therefore, only He is able to draw up a perfect plan for man’s life and keep him from annihilation. God, the Exalted, has presented this plan through outstanding and eminent men picked from among people, who are free from error, so that man may achieve his all-out evolution by seeking guidance from this plan.
Another function performed by the prophets is that they are the first to apply the divine law, that is, besides delivering the law, they teach men to practice the law. They are the visible embodiments of that law so that others choose the divine law as the plan for their lives by modeling them. Therefore, the faithful people believe that God has sent prophets to direct men toward the path of evolution and felicity in every era.
Someone asked Imam as-Sadiq (‘a) “Why prophets are appointed?” The revered Imam replied, “having proven with irrefutable arguments the existence of an All-wise Creator who has brought us form non-being to being and having established that God is not material and is superior to every other creature, and none can see or observe Him, so that he might talk to Him about the state of affairs, and put his questions to Him, therefore, it is inevitable that He must have messengers and prophets who guide people toward felicity and explain what is harmful for them and in every era, there must be a guide among people so that earth is not bereft of God’s proof.”[^1] [^1]: ‘Usul al-Kafi, vol.