One of the reasons why the Prophets were sent is that mankind might have no argument against God in the Hereafter. Regarding this, the Qur’an says:

Messengers bearing good tidings and warning, so that mankind might have no argument against God. (al-Nisa’, 4.165)

Mankind, who have followed many so-called guides or leaders only to be led astray, have reached the truth through the guidance of the Prophets, upon them be peace. They were the servants of God created for a special mission. They were ‘Prophets’ in the wombs of their mothers. Their birth was marked with extraordinary events. Their lives resembled a beautiful symphony, being perfectly harmonious and balanced. Their words came out of their mouths like a sweet melody and penetrated into souls like a perfect penetrating lyric; the whole of existence, animate or inanimate, hearkened to them. Among the miracles of the lord of lords, upon him be peace and blessings, is that trees and rocks greeted him and answered his call. In his well-known Qasidat al-Bur‘a, Busiri says, Trees answered his call, prostrated. When he called them, trees cleft the earth and came to him. Besides living beings, inanimate things, too, acquired a meaning through his advent, and existence attained the state of being ‘cosmos’ out of the chaotic state, and each thing became a tongue glorifying God with praise, as declared in the Qur’an:

There is not a thing that does not glorify Him with praise, but you do not understand their glorification. (al-Isra’, 17.44)

There is an extraordinary harmony in the universe, which displays the existence and unity of God. Nothing is created in vain. Like every other creature, man also was not created without purpose. The Qur‘an declares:

Does man think that he will be left aimless? (al-Qiyamah, 75.36)

If the Prophets had not been sent, man might have had an argument against being punished in the Hereafter. But, as the Qur’an states, We never punish until We have sent a Messenger (al-Isra’, 17.15), God would not punish anyone without having sent them Prophets. He sent them so that the good might be distinguished from the bad. After the Prophets, mankind would no longer have any argument against God’s punishment or reward.