Divinity cannot be known unless messengers are sent.
The sun necessarily entails its light; for the sun cannot be known unless it spreads lights. Similarly, Allah necessarily requires messengers.
A beauty of the utmost perfection wishes to manifest itself by means of an indicator, and an introducer.
A perfect work of art of surpassing beauty wishes to reveal itself by means of town criers who attract the attention of all to that beauty.
A possessor of treasuries filled with wondrous miracles and marvellous precious things wills and wishes to make his hidden perfections manifest by presenting them to the eyes by means of jeweller introducers, and describing exhibitors.
Is it at all possible the universal kingdom of universal Lordship should not wish to proclaim its unity and eternal independence and besoughtness by means of messengers?
Allah has made this universe resemble a palace decorated with wondrous, marvellous, intricate arts, for the sake of its being beheld, by way of ornamenting this universe with His works of art which express the perfections of all of His Names; is it at all possible He would not appoint therein guiding teachers?
Allah, the Owner of this universe, would of course make His messengers reveal the purpose and objective in the continual transformations that this universe undergoes; and these closed, hidden deep mysteries, as well as the riddle of the three difficult questions asked by existent beings, ‘from where [are you coming]?’, ‘to where [are you going]?’ and ‘what is your duty?’
Allah, Who has made Himself known to ‘conscious beings’ by means of these beautiful works of art, and Who endeared Himself to them by means of His precious blessings, would of course let them know by means of messengers what it is that it pleases Him to see in conscious beings, and what He desires from them.
Allah has created mankind and prepared them for universal servanthood with respect to innate capacity. He would of course wish to turn their faces away from multiplicity to unity by means of teachers and guides; He would not let them be beguiled by multiplicity with respect to intellect.
Prophethood involves a very great number of different duties like these; and every single one of them constitutes a conclusive proof that Divinity cannot be without messengership.