I want to know the answer to the following question:
What verse in the quran expresses the necessity to the appointment of the prophets?
All the background I'm provided with is that "Shias believe that Imamah is of the Principles of Faith (Usul al-Din).As the verse 4:165 of quran expresses the necessity to the appointment of the prophets; so after the demise of the prophet who will play the role of the prophet; till the people have not any plea against Allah.". Is that enough to answer the question?