Prophethood is not something acquired by a person who proves himself worthy, nor is it granted in recognition of piety. Prophethood is an office to which God appoints a man in order to fill a particular need. The Qur’an mentions four conditions under which prophets were sent to the world:
- When no prophet had ever been sent to a people before and no divine message had reached them.
- When the message of an earlier prophet had been forgotten by the people or the teachings of former prophets had been altered with time.
- When a second prophet was needed to assist a first one.
- When a people had not yet received complete instruction from God.
In each of these cases a prophet was appointed to convey divine revelation, updating previous messages and correcting deviations that man had introduced into the religion of God.
After God’s message was completed through revelation to Muhammad and its preservation guaranteed, there was no further need for messengers to convey revelation; only for teachers and reformers to remind people of what God had revealed.