وَلَوْلَا أَن تُصِيبَهُم مُّصِيبَةٌ بِمَا قَدَّمَتْ أَيْدِيهِمْ فَيَقُولُوا رَبَّنَا لَوْلَا أَرْسَلْتَ إِلَيْنَا رَسُولًا فَنَتَّبِعَ آيَاتِكَ وَنَكُونَ مِنَ الْمُؤْمِنِينَ (47)
(28:47) (This We have done) lest, when a calamity befalls them in consequence of their own misdeeds, 'they should say, "Our Lord, had You sent a messenger to us, we would have obeyed Your Revelations and been among the believers. " *66
*66) This very thing has been presented at several places in the Qur'an as the reason for sending the Messengers, but it will not be correct to conclude from this that a Messenger should be sent on every occasion at every place for this purpose. AS long as the message of a Prophet remains intact in the world and the means of conveying it to others exist, there is no need for a new Prophet, unless need arises to supplement the previous message, or to supplant it by a new message, Nevertheless, when the teachings of the Prophets are forgotten, or become mixed up with errors and deviations and can no longer be relied upon as means of guidance, then the people do get a chance to make the excuse that there existed no arrangement whatever to make them aware of the distinction between the Truth and the untruth and guide them to the right way: so they could not be guided aright. To meet such an excuse Allah sends the Prophets in such conditions so that any one who follows a wrong way after that may himself be held responsible for his going astray.